Call of Duty: World at War hasn't hit the stores, yet, but nevertheless its successor has been announced already: in 2009 another part of the game is said to be released.
Will the successor of Call of Duty: World at War be released in 2009?
During a conference call Bobby Kotick, CEO of Activision Blizzard, revealed, that the game will be developed. But the publisher will leapfrog studios. Therefore it is likely to be Infinity Ward who will make the game, since they already did Modern Warfare. The fifth part of the series, World at War, has been developed by Treyarch.
Furthermore, Infinity War is said to work on a Sci Fi project - transferring the Call of Duty series to this genre could, according to kotaku.com, be crazy enough to be successful but there is no evidence for this rumor.