According to this link:
http://capostatus1988.gametrailers.com/gamepad/index.php?action=viewblog&id=99158
is MGS4 not a PS3 exclusive. Following the history of games MGS was since the Playstation debute never an exclusive (so far as I know MGS1 --> PS, PC; MGS2 --> PS2,XBOX,PC).
In my opinion this would mean that the PS3 will die. There is no game left which is an killer application for the PS3.
My only hope is FFXIII but when I think of the really bad FXII there is no game left worth to buy a PS3.
What is your opinion? Do think MGS4 comes to other consoles? Is this the deadly blow for the PS3?