As of yesterday, the ASP.NET MVC Release 2 source code has been made available on CodePlex. ScottGu made the source drop announcement earlier this morning. Congrats to Phil Haack and the ASP.NET MVC Team for shipping the source code. It's worth noting, it's not Open Source in the way that it's just a zip file and no outside patches are to be accepted, unlike IronRuby. The plan going forward is to make incremental drops of the source code going forward.