For the record, I've moved away from being a mainly PC gamer, to being a PS3 gamer exclusively. And Crysis looks way better than Killzone 2.
However, I think Killzone 2 will look better than Crysis 2 on the PS3 and possibly the XBox360, if what they said is true (that the console versions are "identical").
Some direct screenshots of both games (unsure what version the Crysis 2 screenshots come from):
http://www.gamesthirst.com/2010/04/10/in-game-crysis-2-screens-vs-in-game-killzone-2-screens/
Crysis 2 just looks...ugly. Everything is all over the place. Texture quality is iffy and the quality varies wildly, no AA, seemingly no AF. I'm sure that on a PC, Crysis 2 on high is going to look fantastic. But the console version looks like it would be the equivalent of the low/medium setting on the PC. I mean, damn, it's ugly.
Crytek are awesome, and they know how to build a powerful engine. But I question their ability to make a power engine that's well optimized, and has the ability to take advantage of what the power the consoles offer. Instead of building a super powerful engine and then scaling down to what the power of the console, they should have scaled up to match the consoles. That way you don't have decent looking buildings in the background, and shitty ground textures right in front of you. It's like they just chose random textures to downgrade, instead of building up each texture so that everything is uniform in quality.
Of course, all of this could be moot if those screenshots came from the PC version on low settings (why they would have released screenshots like that is beyond me though).