Probably cutting corners for the 360 version
PC lives to serve the console.
I like that relationship. 360 gets their version 30fps with drops, tearing, hopefully 720p and some AA, and the normal people get to enjoy it. Then on PC it can easily be pushed beyond to 1080p, 60+fps, AA, triple-buffering, maybe enhanced textures/effects, etc. so crazy people like myself can sleep easy knowing there aren't technical problems. It's pretty awesome for everyone, until they make a poor PC version or stop entirely
honestly, I couldn't care less with how much Crysis 2 pushes the bleeding edge. Realistically I would reach that graphical level, and getting closer would just impact the gameplay in a negative way. The entire reason I prefer PC gaming is because games run smooth, even if it means dropping visual settings. I still don't understand the benchmark fetish stuff of PC gamers.