The first "Orcas" public CTP release of Visual Studio is now available for download as a virtual machine from Microsoft Downloads (Download details: Visual Studio Code Name "Orcas" September 2006 CTP).
Visual Studio Code Name "Orcas" delivers on Microsoft’s vision of smart client applications by enabling developers to rapidly create connected applications that deliver the highest quality rich user experiences. This new version enables any size organization to rapidly create more secure, manageable & reliable applications that take advantage of Windows Vista and the 2007 Office System. By building these new types of applications, organizations will find it easier than ever before to capture and analyze information so that they can make effective business decisions.
As interesting as this release is for its "new bits" value alone, what's equally interesting to me is the means by which we're distributing it - as a virtual machine that you can use with Virtual PC or Virtual Server (both of which are now freely available - Virtual PC Is Now Free!). By using Microsoft virtualization technology, you'll automatically have a sandboxed environment for trying prerelease software. At the same time, you won't have to suffer through the challenge of an evolving setup experience.
To be specific, Visual Studio CTP releases will ship as differencing disks that use a common, Windows Server 2003, Visual Studio CTP base image. With the move to shipping virtual machines, differencing disks will mean smaller downloads than having to download a complete image with each release. If you're unfamiliar with using differencing disks, you should read Andrew Connell's HOW TO: Use Virtual PC's Differencing Disks to Your Advantage.
You can review the Download details: Visual Studio Code Name "Orcas" September 2006 CTP page for what's contained in this release, and you should be sure to follow the directions for installation at the bottom of that page.