Crysis was (and still is) notorious for needing a pretty high-spec system to run well, but Crytek has said time and time again that the engine powering Crysis 2, CryEngine 3, is far more robust, and therefore won’t require the same kind of horsepower to run well. You know where this is going. VR-Zone claims to have the game’s recommended system requirements, and they are as Crytek claimed: not too crazy.
My own self-made PC (Radeon 5970, which has greatly disappointed me vis-à-vis CrossFire performance but whatever, i7 860 OC’d to 4.0GHz, 8GB memory, all running at 1920×1200) would appear to meet the “highly recommended” specs. I won’t be playing in 3D, but what are you going to do?