Microsoft have just announced a new map pack for Halo: Reach, titled the defiant map pack. The maps have been made in partnership with Certain Affinity, who previously worked on Halo 2 maps and the Call of Duty: Black Ops First Strike DLC. The Defiant Map Pack will be available this March on Xbox Live for 800 Microsoft points. It will contain three new maps you can see in the video above and will have new achievements to collect worth a total of 150 gamerscore.
Thanks to CVG for the info and footage.