ive played it and i get over 55fps most of the time, dipped to 35ish when i got to the pink flare and looked at the trees but as soon as the flare went off screen my fps shot back up to 70ish!
Shaders on medium, post processing on low, everything else on high, 1280x1024, 320mb GTS, 2.8ghz c2d 2gb ram, very impressed!
Edit: This was with the new crysis drivers btw.