The server you are accessing at Microsoft may already be virtualized. So far, about 25% of the production servers are running on Windows Server 2008 Hyper-V. About 80% of all new servers at microsoft.com and others will be virtual.
This includes about 350 production servers using Windows Server 2008 Hyper-V with another 300 being ramped up in the next few months. In fact, when you use MSDN or TechNet, you're already on a virtual server. For more infomration about how that system is being rolled out, see MSDN and TechNet Powered by Hyper-V.
Hyper-V technology can be used by software developers or testers looking for ways to increase productivity by reducing the time it takes to build and configure a server for development or test use.
To learn more about what Hyper-V is and how it works, see Hyper-V and to get started see, Step-by-Step Guide to Getting Started with Hyper-V. Hyper-V Release Candidate 1 is currently available. Hyper-V is scheduled for release in early summer.