Recent news from PDC is that the CTP for Visual Studio 2010 and .NET 4.0 are waiting to be tested by you! Chris Koenig’s blog has more information:
http://blogs.msdn.com/chkoenig/archive/2008/10/27/get-your-net-4-0-and-visual-studio-2010-right-here.aspx
You might want to check out what he has to say, because it sounds as if the preview is a little quirky to get started, but if you can’t wait to start downloading the files, go ahead to the download page here:
https://connect.microsoft.com/VisualStudio/content/content.aspx?ContentID=9790
The CTP is packed into a Virtual PC to get you started in a safe testing environment. Good luck, I can’t wait to dig around when I get the chance :)