The first Modern Warfare 3 DLC release will contain:

4 New Multiplayer Maps:
-Black Box
-Piazza
-Overwatch
-Liberation

and

2 New Spec Ops-Modus Maps:
-Negotiator
-Black Ice

The content pack's price
will be at 15$
Enjoy !

http://store.steampowered.com/app/42695/