Quoting from the Microsoft official announcement:
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For Software Assurance customers using Windows Vista Enterprise, we’re adding two new ways to license and deploy the operating system. They are:
- The license right to use Windows Vista on diskless PCs
- The availability of a subscription license called Windows Vista Enterprise Centralized Desktops (VECD) which allows customers to use Windows in virtual machines centralized on server hardware
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The license to use diskless PCs is available at no charge for Windows Vista Enterprise customers – it’s essentially a change to the existing Software Assurance license, providing customers more flexibility. VECD is available to Software Assurance customers for an annual, per-device subscription fee. The fee varies based on whether your business is licensing PCs or thin client.
Microsoft also published a whitepaper about the new VECD license which every hosting provider should read:
This white paper introduces Windows Vista Enterprise Centralized Desktop, a way of licensing Windows Vista for deployment in a centralized, virtualized setting. It then examines how Windows Vista Enterprise Centralized Desktop may be deployed using Microsoft Virtual Server 2005 R2 along with other Microsoft software and technologies. It examines two common deployment scenarios, followed by considerations and recommendations for deploying Virtual Server in support of such solutions. It concludes by examining the key benefits of implementing Windows Vista Enterprise Centralized Desktop on Virtual Server and presenting additional sources of information on the topics discussed in the document.
And finally Brian Madden added some interesting thoughts about this licensing change here.