Today Microsoft posted an official press release available here about Bungie leaving the fold.
Here’s a snippet from the article:

Microsoft Corp. today announced a plan for Bungie Studios, the developers of the “Halo®” franchise, to embark on a path to become an independent company. Microsoft will retain an equity interest in Bungie, at the same time continuing its long-standing publishing agreement between Microsoft Game Studios and Bungie for the Microsoft-owned “Halo” intellectual property as well as other future properties developed by Bungie.

This move basically gives Bungie the freedom to develop titles other than the Halo series, and possibly even for other consoles. Bungie did start out developing the first Halo game for Apple’s Macintosh before Microsoft bought them for the Xbox. Bungie may even go back to some of their old franchises like Myth or Marathon.

The split from Microsoft in no way means they won’t continue to make exclusive games for the Xbox 360. Look at Gears of War by Epic Games. They aren’t owned by Microsoft, yet they sign exclusivity deals to keep their title on a specific platform, and in return Microsoft pays them a butt-load of money in advance to have those exclusive rights.

If Microsoft had never purchased Bungie I’m guessing that the Xbox name wouldn’t be nearly as strong as it is today.

Boom!