Yeah, I'm wondering this too - Quadrant and the Repository were officially canceled, but supposedly M was still going to live on (although I think a lot of people were skeptical). However, since then Don Box has left the SQL group (or wherever it is he was) and joined the Xbox/TV/entertainment division, and he seemed to be the main remaining person championing it - after Brad Lovering and Doug Purdy also left Microsoft - so that makes me suspect it's dead. 

Too bad, I think most people were just confused by the Oslo project but M was the one piece of it that did seem pretty cool.