I ve played the demo.
Pretty good game although not my style.
The sound made an impression on me. It is very realistic. Gun shots echo on open spaces like the real thing.
It is also very heavy on destructible environments. Houses, trees, poles....they can all be blown.
Character models are some of the best Ive ever seen.
I cant comment much on the gameplay since it is not my type of game, but I think it had much more variety than COD4 although it was slower paced