In an interview with GamesIndustry.biz, head of Microsoft Game Studios Phil Spencer talked about where the Halo franchise is headed (among other topics) and confirmed that multiple development teams are indeed working on numerous Halo projects.
"There's more than one team building Halo games right now. There are more than two or three teams building Halo things right now" says Spencer, adding "some of them we will own, some of them we won't." Hmm, interesting stuff. Currently, we're aware of two Halo titles, Halo Wars and the Peter Jackson projected dubbed Halo: Chronicles. So, if there's more than three teams working on games, how many Halo titles does that equate to and when do we get to hear about them? Whore that Halo franchise MGS, whore it out good!