A new Snake, a new clone, a new story.
Takes place after MGS4.

But then again, its Kojima and he is not bound by logic xD

if this according to you is before PW, then how Snake has 2 arms in PW ......¬_¬

Also, Kojima said that the hair looked grey because of the lighting effects.  And then he released another pic showing brown hair in GZ.

If these events shown are actually the events prior the cloning of BigBoss, (before PW), I dont think they are "truthfully" represented in the video.  I think all is an illusion made by kid Psycho Mantis.  By the end of the video you can see a kid flying when the soldier is about to shoot bigboss.

look at his beard, and his hair is a lot more brown in the new trailer and he is more younger in the face. Psyco mantis could be doing this, but will still represent what went on when he was in a coma. Also, the missing arm could be another representation of a past event. Or perhaps when he went into a coma, he broke his arm in some way. But he was in a coma at some point, liquid explain this in metal gear solid 1.

kid flying => Psycho Mantis.

I know that what liquid explained happens when Bigboss is about to get cloned.   But still this soldiers equipment is the same as in GZ, which shows that they both happen around the same time. 

That is why I think: (copy pasting my previous comment)

What I think is happening is that BigBoss has been captured and they are using the powers of Psycho Mantis to dive into his mind and get some information, and all what is happening about the whale, the flaming Pegasus and the killing is only happening in Snake´s mind. The one bandaged is the dude from the ground Zeroes trailer, and maybe in that illusion Psycho mantis is making him help snake so that he trusts him, and give them the information they want. OR the burned dude was really there.

The arm thing most probably refers to something that actually happened in the game. Maybe he broke his arm, so in the illusion it is like a prosthetic arm because he can not use it.

But in the end, the Illusion is made around the memory of the events after he was in coma.

Or Snake is just FUCKING DREAMING ABOUT HOW HE ESCAPED!!!! LMAO!

You're trying to make sense of a MGS game. Good luck...

Remember this could be a dream and he can also dreaming of the current soldiers, or maybe this is some flash back, we won't know until the game is released. But I can almost guaranteed you the beginning of trailer represents when he was getting clone in a coma or around that time. And yes it appears to be psycho mantis. Also, just because they have same gear doesn't mean anything, again mgs2 the main terrorists carry same gear on both the plant and the tanker.Also, this is my wild guess, but the guy with the burned face(original trailer) is Psycho Mantis father...... DUN DUN DUUUUUUN.And Psycho mantis kills him later on.If I somehow get this right, I WANT A COOKIE.

Kojima will deliver your cookie...but it will be filled with nanomachines...that are controlled by the patriots...but really Liquid will be laliluleloing them and hack the cookie...then Big Boss will break in and eat the cookie to foil their plan which was all part of his plan to get Revolver into their bakery to use a different kind of sugar than they wanted to.  It's all pretty straightforward.