I strongly doubt it... that's already been suggested on HBO, and I wrote why I thought it wasn't so there, but with the server slowdown I'm reluctant to put a link here.
However, I can put a link to my reasoning that it's Bungie here: http://www.bungie.net/Forums/posts.aspx?postID=368244
In the HBO post, I also pointed out that I don't think it'd be doing Wideload any favours by tying them to Microsoft and Bungie; they're all about being an Indie studio, after all, and reversing the trend that led to the Big Studio system in Hollywood back in the '30s.
-- Steve's looking forward to Wideload's new projects, but doesn't expect to see much tangible until early 2005.