Even though Modern Warfare 2 (Call of Duty 6) has yet to make a major appearance (with the exception of a TV spot), Treyarch has already started working on Call of Duty 7. This was confirmed by Senior Editor David Kim’s LinkedIn profile:

“I am currently on my second title as a senior animator in the games industry with Activision / Treyarch on Call Of Duty 7. Previous to that I specialized as a previsualization artist for various productions.”

The game is expected to use the CoD6 engine, as World at War did with Call of Duty 4. There are even rumors of the game taking place in Vietnam, which isn’t hard to believe since that is one place the Call of Duty franchise has not visited.