From a tweet by @HumanCompiler, http://codeplex.org, an Open Source Foundation with a mission "to enable the exchange of code and understanding among software companies and open source communities". I know Microsoft has gotten a lot of flack over their stance on Open Source in the past, but it truly does look like they're getting into the game in a big way now. I see this as a very good thing, and it will be interesting to watch what comes out of this.
BTW, cue Ubuntu's rants on this topic.