Don't sell the game short. The framework is already there from Call of Duty World at War. We're apparently not getting MW2 anytime soon, so 6 devoted months (surely they've been working on this since World at War was finished, so we're talking a good year) porting a 2 year old game that runs on the same exact engine, and with less features, than a game that was released last year, should be plenty of time.