There we go.
It's finally confirmed @ Konami's conference.

http://e3.g4tv.com/e32009/pressconference/konami/16/

3:33
Raiden shown. Here comes Rising!
3:33
Trailer time.
3:34
Same one that played at Microsoft's press conference so far.
3:34
PS3 LOGO confirmed on the title screen.
3:34
This is multiplatform people.
3:34
PS3 / Xbox 360
3:35
This is the "next series of Metal Gear" for the next-gen consoles.
3:35
This is a stealth espionage action game, but the main character will be Raiden.

MGS:S is coming to 360 this is the last thread.

Umm what? I think we kinda knew that, this thread's meaning is to confirm it on PS3/360. My post above.. Read it.

MGS:S what in the sam hell is that?

Kojima didn't really want anything to do with MGS4 either.  He wasn't very happy about it as well.  He kinda got forced into it.

But look at the outcome, I wouldn't say he is very dissapointed to make another game.

what would really clear it up to me is...will this game be part of the main series or is it a spin-off?

Don't you remember when he said that the finished product wasn't very good and blamed it all on the constraints placed on him by the hardware?

The PS3 version is mainline, the 360 version is a spin-off.

On a serious note... MGS:R is likely to be the start of a whole new story in the MGS series.