Halo 4, starting as scheduled on January 21 with Episode 6. The next two episodes of the co-op campaign are coming on January 28 and February 4. After that, two more as-yet-undated episodes will conclude the first season, the likely word of pertinence being 'first.'
343 Industries is also releasing matchmaking updates alongside the Spartan Ops episodes. Joining episode 6 on January 21 is a new 'Forge Test' playlist which rotates around some of the smaller Forge maps like Relay. Pioneer and Pathfinder specializations are also being unlocked then. Accompanying the following episode on January 28 is a Grifball playlist, along with Engineer and Stalker specialization unlocks. February 4 brings the Team Doubles playlist, with maps limited to two teams of two, as well as Rogue and Tracker specializations.