ASP.NET MVC RC Available!
I haven’t tried upgrading an existing site yet, but new website creation works well. The only thing I’ve seen so far is that if you create a unit test project to go with your web app it won’t compile. Luckily, all you have to do is include the proper namespace reference to your controllers at the top.
You can find out more in ScottGu’s rather long post on the RC bits.