The next Halo?

Ok, so most people already know about Halo:ODST, which comes out this fall, but has anybody heard about the next game? Yes, the Bungie team is now well on its way to creating the next halo: Halo:Reach. Could this be possible you say? Bungie just finished three new maps in its mythic map pack for Halo 3, and it is working on ODST, but even another game? Bungie has already sent out a new trailer for this game- http://www.youtube.com/watch?v=MqIEvH7sGQ0, and has set a release date for 2010 on the xbox360 gaming system; Amazing...