Well I've played about half an hour of the game so far, after spending almost an hour getting it to change resolution - had to edit the config file manually, and I can't say I'm as impressed as I'd liked to have been. The demo sucked, which didn't help my expectations. Can't say the story is very good, or very well explained and the gameplay is generic CoD style, run to next area and shoot.. run.. shoot.. run.. shoot, etc. While this does work, it's getting a little boring now.
The graphics are very good and it runs ok, thought the areas with grass lag it to high heaven. The people who were saying CoD4 would look better than Crysis were very much mistaken. While they are good, they can't compete. I think GoW/UT3/etc looks better as well. The sound is also of a reasonable quality, though nothing new in any way.
I've not tried MP yet.