A calendar on the Call of Duty site outlines the release schedule for all of the Modern Warfare 3 DLC that will be released this year. As well as the two maps they've already teased, ten more multiplayer arenas, six more missions and two new modes are listed. That makes up the 20 chunks of DLC Activision promised a week or so ago.
The schedule is aimed at those signed up to Call of Duty Elite, though the extra missions, maps and modes will make their way to the PC eventually. Black Ops DLC took about four weeks to cross the desert that separates Xbox Live land and PC gamer world. Check out these Modern Warfare 3 screenshots for an early look at the first two maps, Piazza and Central Park.