I'm suprised out of all the footage thats been out I've still yet to see head bobbing, it looks exactly like counter strike where you just kinda glide across the floor. I'm sure they'll add it but its suprising that they havent already considering they've already spent alot of time with trophy kill animations.
It's actually hard to think of a first person shooter that doesnt have headbob, infact the only three that come to mine are the first AvP, counter strike, and fallout3.
Even the slightest smallest headbob would be neat to have, AvP2 had a very nice low level headbob that didnt distract your aim, but it was still noticeable.