The official Call of Duty: Elite website appears to have the release dates of the 3rd and 4th DLC packs for Call of Duty: Black Ops 2 hidden within its coding—at least according to @TwiinSane, who claimed the discovery.
The third DLC is listed for a July 2nd release while the fourth (and final) DLC has a release date of August 27, both of which refer to their respective releases on the Xbox 360, which has a one-month exclusivity over its counterparts on the PC and PlayStation 3.
Though it can't be fully confirmed as Activision has not put out an official statement regarding its release plans, we have no reason to believe that the release dates provided are far from the truth.
Presently, there are two DLC packs for Call of Duty: Black Ops 2, titled Revolution and Uprising, both of which add new maps to the game's zombies mode and competitive multiplayer mode.
Given the names of the previous DLCs, there's a good chance that the gang at Treyarch are going to keep up the trend of naming the DLCs synonyms of the word Revolution. Expect them to be named things like Insurrection, Insurgence, Rebellion, or Revolt.
Thanks Gearnuke.