Its going to be a lot harder to get a very good score if you are camping compared to mw2. In MW2, you can sit in one room the entire game and post 30-3 all day long. With the maps being more balanced, no stopping power/more recoil, killstreaks do not stack, claymores are harder to use (Dpad fuction, No Scavenger Refill).
So far from ALL of the BO videos I've watched, the only time I saw people camping, was in that one Wager match game mode, One in the Chamber. I think it was at the end when it was 1 vs 1 anyways.