In words of Microsoft itself, whether virtualization is an important component of your existing infrastructure or you're just a Virtual PC enthusiast, the latest version of Virtual PC (2007) is now available for download free of charge. Operating system support includes most versions of Vista, XP, and Windows Server 2003.

Use Microsoft Virtual PC 2007 to run multiple operating systems at the same time on the same physical computer. Switch between virtual machines with the click of a button. Use virtual machines to run legacy applications, provide support, train users, and enhance quality assurance.
On a somewhat related note, Microsoft also unveiled this week the public beta of its video sharing service Soapbox, which is meant to compete with YouTube and other similar sites. You may find it relevant that the 'Windows Live' moniker has been removed from Soapbox, which until this week was available to users by invitation only. This is yet another of Microsoft's Live services that return to its MSN naming convention, with the popular Hotmail being perhaps the most prominent example.