Get your early dose of MVC goodness for Visual Studio 2008 here (and here for the MVC Toolkit extras).
There's interesting mention of a few other items included in the extensions preview. One thing I've not followed closely is ADO.NET Data Services. The ADO.NET Entity Framework is billed as "a modeling framework that enables developers to define a conceptual model of a database schema that closely aligns to a real world view of the information". I'm very interested to see how this competes with something like LLBLGenPro (or even if that's it's intention in life).