Let this be a reminder: Bungie is no longer Microsoft's plaything. In an interview with GameIndustry.biz, Community Director Brian Jarrard indicated that once Halo 3 Recon is out the door late next year, the team working on it will move into territory unknown. "But I think when this project wraps up in a couple of months that will be the time when that team moves on to something else, and part of that team will move on to something else and part of them will probably be absorbed into one of the other projects that are already on the way," he said.
Granted, there's a lot of time between now and the Fall 2009 Halo 3 Recon release, so Bungie will be knee-deep in Halo for another year, at least. Provided none of Bungie's other teams tackle the space-loop saga, Microsoft has already assembled a new dream team to keep Halo alive.