Yeah. Call of Duty 5 is in development by Treyarch (not Infinity Ward) and is taking the series back to World War II after Call of Duty 4: Modern War. Activision is really on a roll with their whole "we're going to exploit our franchises as much as possible" mindset.
There were rumors floating around a while back relating to Infinity Ward purchasing the rights for major Call of Duty iterations back from Activision so that Call of Duty X would always be an Infinity Ward title and any off-shoots would be unrelated to their superb work.
Anyway, the fact that it's set in the Pacific Theater makes the move back to World War II less moronic, but it's still a head-scratcher. At first I thought it was going to be set in the Vietnam War and that would have been amazing.