Luke, a PM on the C# IDE team has started a blog... should be a good source of info, especially around the new Express Edition.

Intro + C# Express
... The project that I’ve been working on for most of my time at Microsoft is the Visual C# Express Edition.  So as you can probably guess, I’m really excited that the betas of the Express editions are now available for download.  It’s been really great seeing all the feedback we’ve already received on the Express idea after less than 48 hours.  ...