I don't know, it was okay, better than Hellgate London (Their demo stunk the big one. Was pretty hyped about it until I played the Demo, now it's waaaaaay down on my list, and probably won't get it unless something changes with it, depends on what reviews say). It was also better than Quake Wars overall, tried UT3 demo however, and that one looks like it will be fun as well.
Biggest problem in CoD4 Demo is that half the time they are telling me someplace to go, I see the little thing on the screen where I should go, but it still is a pain to figure out exactly where they want me to go so I end up wandering around like what a good soldier shouldn't do.