One of the sites to keep tabs on is the ASP.NET home section of CodePlex.  For those not familiar, CodePlex is Microsoft's free hosting site for their version of open source software.  Software hosted there is not under the GPL, but a similar type of Microsoft open license.  It has seemed to evolve into Microsoft teams areas for exposing software they are working on and that can have visibility exposed to the outside.  It is also their answer to SourceForge.   From this page on CodePlex, there are many links to what the ASP.NET team is considering and working on in different projects.

ASP.NET - Home