Well, the scenery does look pretty nice, BUT ... they don't have to spend any CPU power calculating Damage models. They don't have to use any CPU power to calculate bullet trajectories. Does it have moving vehicles ? Smoke ? ( maybe there's a Forestfire addon ). What's the water like ? Do they cater for up to 128 planes on a map ?
So maybe, just maybe CoD isn't going to have photo-realistic terrain, but, y'know, I kinda like the combat bits