343 have confirmed via their Halo Waypoint blog that Halo 4 will receive its first DLC pack, as previously reported, on December 10th. The pack will contain three new maps (Wreckage, Harvest and Shatter).
A new game mode called Extraction is also deploying to multiplayer the same day. The mode is 5 vs 5, objective based game in which Spartan teams are tasked with extracting assets from different sites around the map.
The pack costs 800 MS Points if you don’t own a War Games Pass, if you would like to purchase a Pass it will cost you 2000 MS Points, a saving of 400 MS Points when the other two packs release.