Trailer looks great. Infinity Ward seem to have a knack for presenting a completely believable image on the screen: I think it's part lighting, part animation, and part art direction.
I'm not particularly enamoured with the voice acting, although there isn't much to go on yet. The VA for Price in MW was pretty hard to fault though so the bar has been raised pretty high.
My biggest concern though is the character design; mohawk on an SAS trooper seems a little out of place, plus what's with the guy with facemask, sunglasses and ear muffs? I'm reminded of the Peril Sensitive Sunglasses from Hitchhikers Guide to the Galaxy..