Activision has come closer to identifying the specifics of the Modern Warfare 3 DLC schedule for Elite members, posting a calendar that shows what kind of content will be available every month through September. Don't worry: it's just text and images, not a video of Rob Riggle reading the schedule out. Yet.
February offers just one map, and April and July will have two maps each; aside from that, every month has some combination of maps, missions, and modes (modes in June and August). You can see exactly which combination will be available each month after the break, but Activision isn't revealing names until the current month, it appears.
Update: See a walkthrough for downloading Elite content in the video above.