A few months ago, I put out a preview of a ASP.NET 4.0 CMS called "Purple" (named for the official color of Dallas Theological Seminary). 

I'm now pushing updates to Github, so if you're interested go grab a copy here

http://github.com/johndyer/purple

About Purple

Purple is a CMS that uses .NET's URL Routing to quickly create a website using normal .NET tools like Masterpages and ASCX controls. It has versioning controls for every page and allows you to edit in page rather than through a backend editing area and stores everything in either XML or SQL for rapid development.