Activision has announced a nine month schedule for Modern Warfare 3 DLC. Starting on January 24th, and ending in September, the content will be made available first to Premium Elite members on Xbox LIVE “followed by additional platforms at a later time.”
We are promised ” brand new multiplayer maps, Special Ops Missions, new game modes and more.”
Modern Warfare 3 owners who aren’t signed up to Premium Elite will still be able to buy the DLC “a la carte” via Modern Warfare 3 Content Collections which will be available in March.
Source: Press Release