I found this on the Call of Duty site and have yet to see anything about it.

http://www.callofduty.com/contentcalendar

Jan: 2 Maps

Feb: 1 Map

Mar: 1 Map 2 Missions

Apr: 2 Maps

May: 1 Map 1 Mission

Jun: 1 Map 1 Mission 1 Classified (New Mode?)

Jul: 2 Maps

Aug: 1 Map 1 Mission 1 Classified

Sep: 1 Map 1 Mission

(All Subject To Change of course)

So all in all, we can expect 12 New Maps, 6 New Missions and 2 Classified Drops.

Considering each Map Pack usually came with 3 new multiplayer maps for US$15 (not talking about Zombies), if would have cost us at least $60 for downloads.