A new Halo: Reach update is coming to XBox Live on March 29th (apparently). It brings in new game types and more custom maps designed by the Halo fans in the community.
As for the update, the April Matchmaking revision will see a laundry list of changes to Halo’s online universe. These updates include the addition of new game types and more community-made maps into the multiplayer hopper, as well as the implementation of a list of minor tweaks.