On Elite TV, it was teased to us about the first DLC for MW3. The DLC will drop to XBOX players first (remember, there's that exclusivity that goes through the end of the year) on January 24th.
In the video they discuss that it's not going to be just maps, that they're able to bring some new types of DLC to the table.
You can setup a free account at COD Elite and watch the video under Elite TV > Roll Call
Sneak peek at the map called "Park":