My predictions:

- Nintendo DSi Ware -

More Art Style Games
major 3rd party franchise coming to the service (Final Fantasy?)
Virtual Handheld service, (Game Boy, Game Boy Color, Game Gear games)

- Nintendo DSi -

Nintendo announces first batch of DSi only carts
Very few 1st party (Pokemon Snap 2?)
Lost of 'indy' developper support

- Nintendo DS -

N/A Launch dates for Mario & Luigi RPG 3 and The Legend Of Zelda: Spirit Tracks
Emphasising that Nintendo will support both the Lite and DSi
No new games from Nintendo
Strong 3rd party support (Castlevania? Contra 5? Resident Evil spinoff?)

- Wii Virtual Console -

Nintendo announces more Nintendo 64 games now that storage soluton is here
Sega Saturn games
Atari 2600 games
more Arcade games

- Wii Ware -

More Art Style games
More 3rd party support
Nintendo sill ignoring

- Wii -

Core titles from Nintendo (1-2)
Expanded titles from Nintendo (3-4)
3rd parties go core (Red Steel 2, Dead Speace, Resident Evil etc...)
No Kid Icarus
No Zelda Wii
No Metroid
Sin & Punishment pushed to 2010
possible Donkey Kong revival
Mario sports or Mario part 9 announced
Nintendo's core games will be from obscure franchises
Possible Pikmin 3

I really don't think Nintendo will present their E3 conference without showcasing either Mario or Zelda. I think most people will be disappointed without seeing a major title like that, and I don't think Nintendo is stupid enough not to show the game at E3.

About F-Zero, a game like F-Zero won't take more than 16 months to be developed, so I don't see why Nintendo won't be able to show it even if we assume the game has been in development for 8 months, and I think in a way, this game can take advantage of Wii Motion Plus.

As for a big Sony RPG, I am also doubtful about it, but I do think a big RPG is in development from Sony Japan Studios.

KH for Wii is very likely to happen, but I also don't see it being announced at E3. :/

Oh, and notice that I am not expecting ZoE3 to be shown at E3 '09.

Sony will dominate E3

PSP Go
New motion sensing controller for Ps3
God of War III, Uncharted 2, GT5 = Win

I have nothing to say about the Wii so dont be surprised......

• New Xbox 360 Model (Slim) to be announced<-----I doubt this alot!

• I expect Xbox 360 to be released bundled with a new motion sensing device from 3DV Systems, the creators of ZCam, which MS have recently acquired<---Maybe.....

• A Halo game from Wingnut Interactive<------nope

• Rare to unveil two new games - One for XBL, and one disc-based<-----Your proly dead on

• Forza 3 to be in playable form<----yeah

• Alan Wake to be in playable form (+ release date)<----that would be good news

• New game from Bizarre Creations <---cool if it happens

• New Mistwalker product (Maybe for TGS)<---maybe

• New Ignition Entertainment exclusive title<---the SNK publisher?

• Some sort of Modern Warfare 2 exclusivity - like exclusive beta, exclusive DLC, etc.<------that would kill

• Halo ODST, Mass Effect 2, Splinter Cell Conviction, Lost Planet 2, etc.<------yep

Not expecting:

• Versus XIII multiplatform announcement<-----nethier am I but look what happened last year

• You Are In The Movies 2 :)<-----LMAO

Sony 

I personally think Sony will target the Hardcore market with PS3 for this Christmas while trying to broadening it's market with PSP, I think Sony will focus most of their E3 presentation on PSP, which I think will disappoint some people. 

Shockers: 

• New PSP announcement (PSP-4000) with its huge upcoming line up<---yes

• New Metal Gear for PSP or a Team ICO PSP game/remake.<----Nope, as for ICO..Maybe but not likely

• Three big new PS3 game announcement - One from Team ICO, another from one of Sony's Europe studios, and one from Sony Japan (maybe an RPG).<----They should have something....That Dragoon game anyone?

Games:

• God of War III demo and a release date for late 2009 (December)<----- I wish, if i get this job next week im going on a 20$ a week plan to get a pS3 in 5 months

• Uncharted 2 release date and single player demo<-----yep

• Heavy Rain to be in playble form (+ release date)<-----you better hope

• M. A. G. Shadow War beta detail and release date<-----MAG might...I don't know....It's not that big a deal to me not to have this on 360

• Ratchet & Clank: A Crack In Time demo<-----Sure why not

• GT5 and maybe GT PSP<---sounds like sony to have Gt for PSP this E3

• Lost Planet 2 or Mass Effect 2 heading to PS3<----Lost planet is a maybe.....Mass Effect 2 is highly impossible since the game maker asked people to have thier game saves ready(Your Mass Effect game save will do something in part 2)
  

• Few new unique PSN titles<---don't doubt it

• Huge PSX library on PSN<----Nope!

• WKC, Ninja Gaiden Sigma 2, Quantum Theory, WarDevil, etc...<----yeah yeah
  

Not expecting:

• Wii-mote like controller <-----im actually expecting this

• Zone of the Enders 3<-----Kojima and his stunts....Oh well

Dont think so......I give it to Nintendo this year...I mean there is no way not to smell Zelda this year...

Everything true, but I dont think that Square Enix had time or has time to work on a kingdom hearts game.

Hmm

• Splinter Cell: Conviction
• Forza 3
• Halo: ODST
• Rares new games

all 2009 release dates.

• Alan Wake 2010 release date (Early)
• Lionheads new project annoucned with no release date

Thats about all I can think of for the Xbox 360.

Someone should make an official sticky thread =/

360 games dont' sell well in japan. And KH like FF they like pushing boundries. So I suspect It will be treated like FF13. 1st anounched for PS3 then ported over to 360 for everywhere but japan. (then released on the 360 in japan with NA launch)