Call of Duty 6 (Modern Warfare 2) isn't even out yet and there are already rumors popping up about Call of Duty 7. GameSpy heard rumors that the seventh CoD game will be developed by Treyarch, it will reportedly feature Vietnam, Cuba, Africa and the Soviet Union.
Mentioned were Vietnam War era tunes, as well as Cuban, African, and Soviet Union music. The source says Call of Duty: World at War's senior producer Noah Heller is involved, so it looks like Treyarch is once again developing.
Credibility to the change from WWII is added by Heller himself who last year said they "are showing the final battles of the Pacific and the European Theatre and that lets us put a close to the war. I'm sure game companies will be making World War II games for years to come and World War II is a very classic war. But we're happy that we put the war to bed."