Though Activision's official calendar didn't alert fans to the change, today the company has said that they will be launching three new FaceOff maps for Modern Warfare 3 competitive multiplayer, along with a brand new Spec-Ops mission as well.
The three new FaceOff maps will be Vortex, Intersection, and U-Turn. While the new Spec-Ops mission is confirmed to be called Arctic Recon, and Activision even tweeted an image/screenshot of that which you can find below.
There's no word on when these maps will become available for either regular non-premium Xbox 360 owners or PS3/PC players. Though their DLC timed exclusivity agreement with Microsoft usually means PS3/PC owners get these sorts of things at least within a couple of months.