Well, like I've said before, you'll know it's true when it comes from Bungie. Bungie has posted up a letter to its fans:

Dear Fans, Bungie began as the two of us in a basement, duplicating 800k diskettes, shrink-wrapping Minotaur boxes by hand, and selling games at tradeshows and through a PO Box. What drove us then drives us now: to make the games we want to make, on our own terms, and in our own way.Holding true to this vision allowed us to create the Marathon and Myth series, and has now led us to Redmond to work closely with the Xbox development team. ONI will ship for the PC, Mac, and Playstation 2 later this year. We have yet to decide when and for which platforms Halo will ship.We owe our continuing success to the dedication and loyalty of the people that work here and our fans. We thank you all for that. Our goal has always been to create the best games, and make it fun for our fans and ourselves. Nothing about this deal changes that.At Microsoft we'll set up as the Bungie Studio - sort of a mini-company within Microsoft. It's our job to preserve our personality and culture. With the might of Microsoft's testing, distribution, and other vast resources we'll lead the way on Xbox while holding true to our original vision.We're diving into this with our eyes wide open, and are eager to make it succeed. The last seven years have been a real blast. We hope you'll join us for the next seven, after which we'll blow up the world.- Alex and Jason

They've also posted of a FAQ that gives more detailed information - right from the mouth of Bungie - on recent events.

This is probably as good a time as any to mention that HBO reports Doug Zartman will be leaving Bungie. If so, we'll miss him.