After playing the demo, I must say I'm quite looking forward to this game. It's more Saving-Private-Ryan style gaming to me than Brothers in Arms which was repetitive with same scenery and same tactics with every fight.
Personal favourites: making the ironsight (the down-your-gun look) more appealing than the crosshair, the way health is handled (no medpacks or % of health shown, rechargable) and the implementation of smoke and frag grenades.
More screens can be found here
More info on the Call of Duty Site
