Mortal Kombat is developed by NetherRealm Studios and is set to release on the 19th of April 2011 Worldwide !
Gameplay
The fighting will take place in a 2D fighting plane, similar to the pre-MK4 era.
The normal blows have changed a lot, instead of having a few punches and kicks divided between high and low, now there's a button for each limb: front arm, front leg, back arm, and back leg. This combines with most martial arts techniques and serves to let more fluid character animations, but does not change much the feel of the game for those who already have experience with 2D games.
The player also can make many special moves and execute them without much effort. Also added with new gameplay is the intro and outro animations. Each character will have a diffrent intro and outro, depending if they decided to do a fatality or not.The controls also refer a lot to Mortal Kombat 3, with the clash limited to a single plane, the fastest pace of struggle, many movements that throw the opponent into the air, and several others that take advantage of aerial combat.
The "run" button will not come back, but there will be a quick dash and paste to the player's opponent and inflict even more damage if they're quick in getting their combo. Also out is the infamous system "dial-a-Kombo", which was introduced in MK3 and was to use pre-defined sequences of buttons to execute "ready" combos. The combos are more akin to those found in MK1 and MKII, consisting largely of chaining regular attacks and special moves together.
Also new to the gameplay, is the Super Meter -
When the player takes damage, the Super Meter gets filled up. There are three levels in the Super Meter.
Draining the first level allows enhanced super moves. For example, Sub-Zero's ice ball becomes an ice beam which is harder to dodge. The second level allows you to use a combo breaker, and the third level unleashes a devastating X-Ray attack.
The game will feature three different one player modes: Story Mode, in which the player assumes the role of several different pre-designated characters and the main plot is told; a tournament ladder reminiscent of the earlier MK games which features a sub-boss, boss, and animated ending for each character; and a training mode which allows players to hone their skills with their chosen character.
Also new to the series is a tag team mode, allowing 2 vs 2 kombat.
Official Boxart
In this thread, we shall keep track of all the announced kharacters and their gameplay videos including FATALITIES !
By the kharacter select menu, it appears there are 26 kharacters, a secret kharacter and DLC DLK kharacters.
The roster above is from PAX 2010.
Update : November 14, 2010
New Kharacter select menu -
As you can see, Sonya and Jax have been added ! 
The konfirmed Kharacters so far,
Scorpion
Arguably, Mortal Kombat's most popular kharacter is out for revenge for the Shirai-Ryu Clan and his family yet again in the re-telling of the first three Mortal Kombat tournaments. The epic rivalry against Sub-Zero kontinues under the manipulation of Quan Chi.
Moves -
Bloody Spear - Scorpion sends out a chain with a tipped Kunai attached to its end, impaling the victim in the chest, and temporarily stunning him/her, allowing Scorpion to pull them close for a free hit. Scorpion's signature move.
Helfire Punch - Scorpion teleports behind his opponent and connects with a punch.
Leg Takedown - Scorpion grabs the enemy with a scissor kick, pulling them down.
Air Throw - Scorpion throws the enemy while in the air.
Hellfire - Scorpion summons hellfire directly below the enemy, burning them.
Flaming Backflip - Scorpion performs a fiery blackflip kick.
X-Ray Move - Scorpion teleports over to the opponent, underneath some flames and connects a skull shattering punch, causing the opponent to fall over. He then stomps on the chest of the fallen opponent, shattering their ribs as he does.
Fatalities -
Slice And Dice -
Leg Cut And Decapitation -
Toasty ! -
It has been konfirmed that Toasty will be returning....though only as a GameStop exclusive pre-order of the game (along with the Klassic Scorpion Kostume). Bit of a dick move imo, as this is an iconic fatality, but it'll probably become DLC in the future.
Mileena
She is back with what is probably her most revealing outfit ever. Though everyone knows underneath all that "beauty" is a half Tarkatan klone of Kitana kreated in Shang Tsung's flesh pits. It is said that she is back with a childish attitude, evident by how she skips around to the battlefield like an innocent little girl...before eating your head.
Moves -
Soaring Sai - Mileena throws two sais charged with energy at her opponent. This can also be done in mid air.
Teleport Kick - Mileena teleports through the ground and appears above her opponent with a flying kick.
Rolling Thuner - Mileena tucks into a ball and rolls along the ground, knocking the opponent off their feet.
Backstabber - Mileena jumps into the air and land on her opponent and stabs the opponent's back with a Sai.
Face Gnaw - Mileena leaps into her opponent, holds on and chews on their face and neck and jumps off, sometimes with a kick (two variants). If backstabber is performed before this move, she will repeatedly stab the opponent's back while chewing on them
X-Ray Move - Mileena grabs hold of her opponent, punches them in the stomach and knees them in the face.
Fatalities -
Tarkatan Kiss -
Body Rip -
Mileena Spikes both her sais onto the feet of the victim, and rips their body off from the hip bones (seen in her kharacter vignette).
Reptile
Aaah...The very first secret kharacter of MK Reptile serves Shang Tsung by protecting the Pit stage and hopes to, one day, return his kind back to their former glory.
Moves
Acid Spit - Reptile removes his mask and spits green acid at his opponent's face.
Power Slide - Similar to Sub-Zero, Reptile slides across the floor with a trail of green fluid, knocking his enemy off his/her feet.
Chameleon - Reptile turns himself invisible.
Running Serpent - Reptile runs behind his opponent and elbows them in the face.
Force Ball - Reptile conjures up a ball of energy which, when hits the opponent, propels them towards him.
X-Ray Move - Reptile stabs his opponent in the eyes, and snaps their neck and follows up with a kick to the ribs.
Fatalities -
Acid Puke -
Head Eat/Invisible Torso Rip - Those who pre-order at Amazon will get access to Reptile's Klassic fatality, which either refers to his Head Eat or Torso rip from MKII. This will most likely become DLC as well, similar to Toasty.
Sub-Zero
Arguably the most popular kharacter in MK (yes, I said that about Scorpion too), the icy Lin Kuei ninja is back and freezing people left and right. It appears that he wants revenge on Scorpion for killing his brother, the Older Sub-Zero. It is unclear whether we get to play as the Older, Klassic Sub-Zero - Bi-Han from MK1 or the post MK1, Younger Sub-Zero, Kuai Liang. I think we get to play as both in the Story Mode, as this is a re-telling of the first 3 tournaments.
Moves
Ice Blast - Sub-Zero freezes his opponent in place, setting up a free hit.
Slide - Sub-Zero slides across the floor with a trail of ice, knocking his opponent over.
Ground Freeze - Sub-Zero freezes his opponent's feet, rendering them unable to move.
Self-Freeze - Sub-Zero freezes himself for a short amount of time. If physically attacked, the attacker will be frozen.
X-Ray Move - Sub-Zero freezes his opponents liver and crushes it with his bare hands and follows up with a skull shattering headbutt.
Fatalities -
Torso Rip -
Freeze and Shatter -
Sub-Zero rips out the opponent's spine with the skull attached through his/her stomach, freezes the body and shatters it using the spine.
Spine Rip -
Exclusive to Best Buy pre-orders along with the klassic Sub-Zero kostume. Probably DLC for later.
Kung Lao
Kung Lao is a member of the White Lotus Society, and a Shaolin Monk and a descendant of the Great Kung Lao who was once the champion of Mortal Kombat. He participated in the second Mortal Kombat tournament after the Shaolin temples were attacked by Baraka's forces, killing his brethren.
Moves
Wind Teleport - Kung Lao goes to the ground and reappears behind his opponent.
Double Pass Teleport - Kung Lao passes twice before appearing behind his opponent.
Hat Throw - Kung Lao throws his razor sharp hat at his opponent.
Aura Spinning Shield - Kung Lao spins like a tornado, launching his opponent to the air.
Dive Kick - Kung Lao dives down with a kick from the air.
X-Ray Move - Kung Lao strikes his opponent in the neck near the windpipe, and as they bend down and try to recover, he chops at the back of their neck.
Fatalities
Buzzsaw hat -
Decapitation and Body Slice -
Johnny Cage
You got CAGED !!!! Johnny Cage is a Holywood movie star who entered the MK tournament just to prove to his movie critics that he can fight. Yeah. Seriously.
Moves
Shadow Kick - Cage slides across the ground rapidly with a kick to the opponent's torso.
Green Orb - Cage throws a curved projectile orb at his opponent. There are high and low variants of this move.
Nut Breaker - Cage does a split and punches the opponent's groin area. 
X-Ray Move - Cage puts his opponent off balance and punches the opponent's groin area followed by smashing his elbow into the opponents spine.
Fatalities
Punch Decapitation and Torso Rip -
Nightwolf
A proud, fierce warrior dedicated to the cause of good, Nightwolf is a Native American Shaman who was able to receive visions from Raiden about the invasion of Earthrealm by Shao Kahn.
Moves
Tomahawk Swipe - Nightwolf uppercuts his opponent with a Tomahawk.
Reflector - Nightwolf reflects a projectil sent at him.
Spirit Arrow - Nightwolf shoots an arrow at his opponent.
Rhino Charge - Nightwolf dashes at his opponent and knocks him/her backwards.
Lightning From Above - Nightwolf summons a thunderbolt which hits his opponents.
X-Ray Move - Nightwolf spins his opponent around and drives two tomahawks into the opponents shoulders and kicks them in the back.
Fatalities
Tomahawk Decap -
Sektor
Sektor is one of the three cyborg ninja's kreated by the Lin Kuei in an attempt to create cold hearted ruthless killers. Unlike the other two cyborgs, Cyrax and Smoke, Sektor was unable to regain his humanity. He was sent by the Lin Kuei to assassinate Sub-Zero during the third Mortal Kombat tournament.
Moves
Chest Missile - Sektor fires a straight missile at his opponent from the compartment in his chest. This missile can be launched upwards so that it hits the opponent from above.
Homing Missle - Sektor fires a missile that follows the opponent before exploding.
Rocket Punch - Sektor teleports under his opponent and gives them a rising uppercut.
Flame On - Sektor burns his opponent with a flamethrower.
X-Ray Move - Sektor fires a chest missile at his opponent and immediately performs a rocket punch, breaking the opponent's jaw. As they fall, he powers up a force palm attack and uses it to break their spine.
Fatalities
Target Practice -
Cyrax
One of the three Cyborgs sent by the Lin Kuei to assassinate Sub-zero. Cyrax was able to recover his humanity due to the efforts of Jax and Sonya.
Moves
Energy Net - Cyrax fires a green net which ensnares the opponent temporarily.
Detonator - Cyrax shoots a bomb out of his chest compartment which detonates after a few seconds. He can chose to launch it near or far.
Exploding Teleport - Cyrax vanishes and appears behind the opponent.
Slice and Dice - Cyrax opens his chest compartment and a giant saw blade appears.
X-Ray Move - Cyrax throws a bomb at his opponent which causes them to launch into the air while upside down. He then teleports up to them and kicks them in the spine. Then he grabs the opponent (still upside down) in mid air and pile drives them to the ground with his foot stamping on their skull.
Fatalities
Energy Net -
Arm Saw Mutilation -
Kitana
Kitana is an Edenian Princess, and the step daughter of Shao Kahn. She was under the illusion that she was Shao Kahn's true daughter. Upon learning that she was being manipulated by him, and her homeland was invaded by him, and that her "sister" Mileena is a clone of herself she goes against his will and enters the Mortal Kombat tournament.
Moves
Fan Throw - Kitana throws her razor sharp fans at her opponent.
Square Wave Punch - Kitana launches into the air with her back facing the opponent and uses her fans to launch herself at the opponent with a punch in the air.
Fan Lift - Kitana uses her fans to make the enemy levitate in the air helplessly.
Fan Swipe - Kitana swipes at her enemy horizontally with one of her fans.
Flying Kick - Kitana flies at her opponent with multiple kicks.
Teleport - Kitana disappears into a violet cloud and appears behind her opponent.
Razor's Tip - Kitana rotates her fans around her, dealing damage in the event of physical contact.
X-Ray Move - Kitana stabs the back of her opponent's skull with two contracted fans and teleports in front of them and stabs them in the eyes.
Fatalities
Flick of the Fan -
Jax
Jax Briggs is the leader of the Outer World Investigation Agency, an Earth Realm Special Forces Unit. He has cybernetic, enhanced arms and is the first African American character to appear in Mortal Kombat.
Moves
Energy Wave - Jax sends out a wave of sonic energy at his opponent.
Ground Pound - Jax sends out a shockwave which damages enemies by punching the ground.
"Gotcha!" Grab - Jax grabs his opponent and punches them multiple times.
Multi-Slam - Jax slams him opponent on the ground multiple times.
Backbreaker - Jax grabs his opponent in mid air and breaks them in half over his back.
X-Ray Move - Jax throws his opponent in the air and brings them down on his knee and breaks their back on it and then breaks their back again behind his neck.
Fatalities
Armless Decapitiation - Jax rips off his opponent's arms and crushes his/her head.
Sonya
Sonya is a member of the Outer World Investigation Agency and the first female kharacter of Mortal Kombat. She is a long standing enemy of Kano who had killed her former partner.
Moves
Energy Rings - Sonya sends out a pink energy ring by clanging her wrists together.
Cartwheel Kick - Sonya performs a cartwheel towards her opponent, kicking them on impact.
Flying Kick - Sonya jumps across to her enemy with a kick to his/her torso.
X-Ray Move - Unknown
Sindel
Sindel, once the Queen of Edenia, kommited suicide after being forced to become Shao Kahn's wife after the tyrant invaded Edenia and killed King Jerrod. She is the mother of Kitana, and one of the most unique kharacters in MK due to her actually being undead at one point and the way she plays.
Moves
Star Screamer - Sindel fires a purple powerball at the opponent.
X-Ray Move - Unknown
Jade
A childhood friend of Kitana, she served among her and Mileena as Shao Kahn's assassins. When Kitana went against the will of Shao Kahn, she was ordered to kill her once best friend. However, she joined Kitana and turned against Shao Kahn to fight for Edenia.
Moves
Razor-Rang - Jade throws a razored boomerang at her opponent.
X-Ray Move - Unknown
Stryker
Stryker is the most hated Mortal Kombat character in the first 3 games.
Originally, thought to be a part of the riot police, but now it appears that he is a SWAT team member in the new game, and will probably bring guns, grenades, batons and tasers into the mix...
Ermac
Ermac is a collection of souls who had died in the many wars of Outworld, and is controlled by Shao Kahn and his Shadow Priests. Due to the sheer concentration of the amount of souls making him up, he has the gift of Telekinesis.
Moves
Hado Energy - Ermac sends a zig-zag beam slithering at his opponent.
X-Ray Move - Ermac uses his Telekinetic powers to lift the opponent to the air and smashes him/her down, head first, breaking their skull. Then he hovers above them and smashes onto his opponent, back first, onto the opponent's back.
Liu Kang
Liu Kang is the Champion of Mortal Kombat, Shaolin Monk, member of the white Lotus society and saviour of Earthrealm. He is the main protaganist of the early years of the series.
Moves
X-Ray Move - Liu Kang performs a cartwheel kick and uppercut, causing the opponent to fly in the air, and kicks them in the face as they fall down, cracking their skull in the process.
Baraka
A ruthless Tarkatan warrior with razor sharp blades extending from his hands, Baraka serves Shao Kahn and murdered Liu Kang's fellow Shaolin Monks before the second Mortal Kombat tournament.
Raiden
The god of thunder and protector of Earthrealm, Raiden leads Earth's Kombatants to Mortal Kombat. After 9 straight defeats to Goro, he is able to conjure up a team including Liu Kang, Johnny Cage and Sonya Blade to represent Earth and defeat Shang Tsung, thus saving Earthrealm.
In Mortal Kombat 9, Raiden plays a pivotal role in the story. When he was about to be killed by Shao Kahn at the end of Armageddon, Raiden sends telepathic messages to himself in a previous timeline, and with his newfound knowledge, tries to alter the events in the first three tournaments in an attempt to save Earth realm.
Goro
This Shokan Prince was Shang Tsung's key to victory in the 9 Mortal Kombat tournaments prior to the tournament in MK1, in the first of which he defeated the Great Kung Lao to become the champion of Mortal Kombat. Goro was the first sub-boss the series had.
Moves
X-Ray Move - Goro grabs his opponent in his lower arms, then puts his upper hands to their head and presses hard.This eventually crushes his opponent's skull. He then throws them overhead and slams them into the floor, damaging their skull further.
Shang Tsung
Shang Tsung is a demonic shapeshifter who needs to consume souls in order to sustain his life. He served as the final boss in the first game. After his defeat to Liu Kang, he was to be punished by Shao Kahn for his failure. However, he was able to convince the Emperor to give him another chance to deliver a chance to invade Earth realm, and regained his youth.
Shang Tsung is seen in the Throne room stage in Mortal Kombat (2011).
Shao Kahn
Shao Kahn is the main antagonist of the series and the ruler of Outworld. Originally served as an advisor to Onaga, the Dragon King, whom he killed to ascend to power. His thirst for power leads him to conquer many realms and attempts to conquer Earth through Mortal Kombat. Yet he finds himself failing to do so by the hands of Liu Kang.
At the beginning of Mortal Kombat (2011), Shao Kahn was about to deliver the final blow to defeating Raiden when the Earthrealm's protector send a message of what was to happen to his past self.
Bonus Kharacter - Kratos
Kratos is exclusive to the PS3 version of Mortal Kombat. He is said to have his own God of War themed stage as well. Fortunately, he does not have any impact on the story mode whatsoever (because that would be extremely lame like certain crossover games *cough*MKvsDc*cough*).
Leaked Kharacters -
The sound bytes of Noob Saibot, Smoke, Quan Chi, Kabal (other than some kharacters who've been konfirmed) were leaked by the official website themortalkombat.com
!
