Quote from the gamespot.com website:
One of the most popular modes of Call of Duty: World at War was its unlockable zombie-apocalypse mode, Nacht der Toten (Night of the Dead). In it, the otherwise realistic World War II-set shooter allowed up to four players to cooperatively defend a house against increasingly large waves of Nazi undead. (Watch the video below to see it in action.) The mode was such a hit that it spawned two iPhone spin-offs and a downloadable add-on, Zombie Verruckt (Crazy Zombie).
Some Visine could really clear up that eye condition.
Though the games share the same developer, Treyarch, there was some concern that zombie mode might not make an appearance in the forthcoming sequel, Call of Duty: Black Ops. Those concerns can now be laid to rest like a reanimated SS storm trooper at the business end of a shotgun. Activision today confirmed rumors that the mode would indeed return, but did not clarify if it would once again be undead Nazis or a new form of shuffling corpse.
Given Black Ops' setting, a more likely contender is zombie Viet Cong, as a good chunk of the game takes place during the Vietnam War. The game's single-player campaign will follow a group of US commandos undertaking various high-risk covert operations in various hot spots of the Cold War, including the jungles of Southeast Asia and the more restless regions of Russia.