I've been replaying Crysis since I got my new video card. I played it stock for a while until I realized that there were patches, and then I updated. In both cases, I have been playing with all graphics settings on Very High. The 260 is handling it very well. Gameplay is very smooth almost all the time, the exception being right after the game first loads. I don't expect that will continue once the alien ship comes into play, but we'll see.
My old card, the GeForce 8800GTS 640 MB would have absolutely choked at these settings. I couldn't even run the first couple of levels on it, let alone the back half of the game. I think I had one setting on Very High and a couple on High, but most were on Medium. Even at those levels, it paused sometimes and had very low frame rates at others.
So, yeah, I'm happy. When the new Crysis: Warhead comes out, it should run even better, as the developers claim to have optimized the engine further.
EDIT: I've played through the whole game, and the only time it really showed any really noticeable decrease in framerate was the final couple of battles aboard the aircraft carrier. Not bad for the "midrange" card.