We hear news directly from Treyarch that the new title War
Call of Duty: Black Ops will, in addition to the traditional offline and multiplayer competitive, even a new online co-op up to four players. We can not know if it will once again mode zombie's World at War Treyarch but the words seem clear:
"We have heard many of the ideas of our own fans and for them we are Box containing a new, unique co-op . We then see, the E3 is drawing near.