ASP.NET MVC Preview 3 is on the web
To be short: Read between lines from here and...
Source code and VS templates are on the Codeplex site http://www.codeplex.com/aspnet, to be precise:
Binaries for MVC Framework Preview 3 are here:
I expect that ScottGu post official announcement on this today.
UPDATE: ScottGu posted announcement on his blog, with detailed explanations and code.