This morning the ASP.NET team shipped the ASP.NET MVC 3 RC (release candidate).
ASP.NET MVC 3 is a pretty sweet release, and adds a ton of new functionality and refinements. It is also backwards compatible with ASP.NET MVC V1 and V2 “ which makes it easy to upgrade existing apps (read the release notes for the exact steps to do so).
A fantastic detailed blog is written by Scott Guthrie. Read and download from here.