It lists the upcoming Halo 4 Map Packs along with release dates:
- Crimson will release on 10th December (that's two weeks today!)
- Majestic will release on 25th February
- Castle will release on 1st April
343i gave a little info on what each map pack contains back in October:
Players will witness the chaos of a clash of civilizations in Wreckage and see a blend of claustrophobic spaces and dangerous exposures. Players will also venture into the human colony environs of Harvest and explore a human foray on an alien moon in Shatter. The Majestic Map Pack includes Landfall, Monolith and Skyline. Landfall’s emphasis is on infantry battles against a glittering ocean on a distant world, while Monolith exposes you to the naked vacuum of space -- and the firepower of opposing teams. Skyline’s distinctly industrial feel provides new challenges in somewhat familiar, but occasionally confined spaces.”
Finally, the Castle Map Pack offers Daybreak, Outcast and Perdition. Daybreak is set in a military facility against the backdrop of an idyllic mountain range, while Outcast plunges you into the warrens, canyons and arches of an alien edifice. Perdition takes players into the heart of an urban sprawl, with tactical speed and situational awareness its key features.
You can buy a War Games map pass which gives access to all three map packs now.