IW/Activision announced the DLC schedule for MW3:
January: 2 Maps -- Liberation and Piazza
February: 1 Map
March: 1 Map, 2 Missions
April: 2 Maps
May: 1 Map, 1 Mission
June: 1 Map, 1 Mission, 1 Mode
July: 2 Maps
August: 1 Map, 1 Mission, 1 Mode
September: 1 Map, 1 Mission