According to the statement, The Noble Map Pack DLC consists of three new multiplayer maps (Anchor 9, Tempest, Breakpoint), includes new achievements worth a total of 250 Gamerscore and will be available on Xbox LIVE for 800 Microsoft points.
Anchor 9 allows 2-8 players to face off in game variants including Free for All, Team Slayer and Team Objective.
Tempest supports 8-16 players and offers a variety of modes including Free for All, Team Slayer, Team Objective and Big Team Battle. Tempest also provides players with a large Forge palette allowing them to create custom map variants.
Breakpoint offers multiplayer action for 8-16 players and supports the Invasion and Big Team Battle game variants.