We've already posted some useful info on licensing servers for a virtual environment, but we also get the question a lot of how virtualization changes licensing for hosted desktop (aka VDI) environments. Well, here are some very useful links.
Virtualization brings about new use cases that did not previously exist in traditional desktop environments. These use cases include the ability to create multiple desktops dynamically, enable user access to multiple virtual machines (VMs) simultaneously, and move desktop VMs across multiple platforms, especially in load-balancing and disaster recovery situations. Microsoft designed Windows Virtual Enterprise Centralized Desktop (VECD) to enable organizations to license virtual copies of Windows client operating systems in virtual environments.
Virtual Enterprise Centralized Desktop Licensing:
http://www.microsoft.com/windows/enterprise/solutions/virtualization/licensing.aspx
More Licensing Details:
http://blogs.technet.com/virtualization/archive/2009/07/13/Microsoft_1920_s-new-VDI-licensing_3A00_-VDI-Suites.aspx
Desktop Virtualization (VDI) Info:
http://www.microsoft.com/virtualization/products/desktop/default.mspx
http://www.vmware.com/products/view/
Hope it helps!
