Announced today, through Halo Waypoint, was the Defiant map pack for Halo:Reach. This map pack contains three brand new maps. Two of which are competitive multiplayer maps and one map for the Firefight game mode.
From watching the announce trailer, the Firefight map is called "Unearthed", and the two competitve maps are "Condemned" and "Highlands".
The map pack appears to have been created in partnership with Certain Affinity, who previously assisted on Halo 2s Blastacular map pack. After researching a bit about Certain Affinity, they also designed and created two of the maps in the recent Black Ops map pack.
In the trailer itself there was no mention of any Bungie involvement but as it was released on Waypoint that doesn't neccesarily mean they were not a part of it. In last fridays weekly update, it was hinted that something was on the brink of being announced.
The maps look great in the video and I'm hoping they make a worthy addition to Reachs map offering.
No exact release date was set, it simply says March 2011. And with that I leave you with the announce trailer.