In a conference call with investors this week, Bobby Kotick, CEO for Activision, announced that Infinity Ward will be the developer for the recently announced Call of Duty 6. Prior to this announcement Activision had said that Call of Duty 6 would be published sometime in 2009, but no other details were released.
Activation's choice of developer shows their “leapfrog strategy” in action. This strategy is where the publisher uses alternating developers to produce a product. For example, Infinity Studios has previously developed Call of Duty 4, while the developer Treyarch did the work for Call of Duty 3, and Call of Duty: World at War (often referred to as Call of Duty 5).
Expect more on Call of Duty 6 in the near future.