http://blog.seattlepi.com/digitaljoystick/archives/168757.asp?from=blog_last3
This is not for Halo 3 ODST made by Bungie and it is not for Halo Wars by Ensemble Studios/Robot Entertainment and it is not for the totally dead Peter Jackson Halo Project.
It is not going to be officially announced until long after Halo 3: ODST ships and Bungie quits working on Halo but they are hiring the people right now to make the new Halo Xbox 360 game. This new game is under the supervision of Frankie's Halo Franchise Development Group.
Looks like they are not going to outsource the development of Halo IV to an external developer but rather build a dedicated team in Redmond to handle future Halo games. Things have been trending this way for a long time now.
I took a screenshot of this job listing in case it changes. This new job it is for a new Halo game being made by Microsoft Game Studios. According to the Job listing it is going to be developed in Redmond and it is going to be for the Xbox 360. There you go folks I am calling it. This is as official confirmation as you are going to get for a long time. If they are hiring major people now I would not expect the game before holiday 2011.
Halo IV to be made by Microsoft Games Studio in Redmond for the Xbox 360.








