I've downloaded and have been working with the Visual Studio 2010 beta, in preparation for a First Look. I have found out a few things that might not be obvious at first glance to others, which I thought I'd share.
First of all, don't waste any time looking for the MSDN library for this beta. There is no local version; it's entirely online. ASP.Net MVC is not yet supported; neither are Azure or smart devices.
This beta supports Silverlight, but not all the pieces come with the initial download. If you try to create a Silverlight 2 project from the built-in template, you'll get prompts to install the Silverlight SDK and runtime. When I did this on Windows 7 for x64, I got the SDK, but for some reason the Silverlight debugging component was not installed. I'm still investigating that. If you want to work with Silverlight 3, you'll need to do a separate download.
One of the most interesting new features of VS 2010 is parallel computing using new classes in the .Net Framework. There are parallel computing samples on Microsoft's Web site.
Please share your Visual Studio 2010 beta experiences below or via e-mail.