Largely known as the Call of Duty franchise's B team Treyarch is "a 100 per cent Call of Duty studio - and it has been for a long time now, long before any of [the Infinity Ward] events occurred," according studio head Mark Lamia in an interview with CVG. Beyond COD, Treyarch also developed Spiderman games as well as Quantum of Solace. I think it's a good thing they are only doing duty. I really think the quality of their games will improve now that they can give the franchise their full attention. According to the interview they even have a team dedicated solely to the multiplayer side of Black Ops,which is a first for the developer.
I'm actually getting more interested in this game than I did for MW2.
Sources:
CVG