Everything is speculation until it's in your hands, which should be a painfully obvious message to anyone who follows the game industry. Hell Halo was originally supposed to be a Mac game, Sonic is on Nintendo now, you just don't know what's going to happen until it's time, even with first party games. The only question is the odds of something based on requirements of software and capabilities of hardware. Then there's the question of the market for a product versus the costs with delivering the product - and also importantly, the markets shrank by releasing a product.
Hell I do know one thing, and that's Crysis could be put onto a PS3 a lot easier than Metal Gear Solid 4 stuffed onto a DVD and despite their insistance no 360 port is coming you seem 100% convinced it's coming. Now you speak about Crysis on PS3 as impossible in the face of them hiring PS3 programmers looking to help them port software.
Does that mean the game is coming to PS3? No, it's no guarantee.
My personal theory about it. They'll test the possibility out when they get the engine itself ported. If PS3 can run it, they'll make a port, if not, they won't. They aren't going to announce the game when they don't even know if it'll be doable. But it seems pretty obvious to me they'll be doing some tech demos.