"Microsoft has traditionally not embraced the concept of VDI. For the
longest time it was actually a technical violation of the Windows
desktop license agreement to use Windows for VDI. Then when Microsoft finally changed that policy, they did so by
creating a license called "VECD" (for Vista Enterprise Centralized
Desktop) which is a new license that's required in addition to your Vista Enterprise license. .. Oh yeah, VECD is only available if you have Software Assurance. ..
Microsoft created a new license bundle called the "Microsoft Virtual
Desktop Infrastructure Suite," which, like most Microsoft products, is
available in multiple editions. This suite is not a new product, but
rather a hodge-podge bundle of most of the different things you'll need
to start using Microsoft's VDI platform. ... The problem is that the "suite" is just a sort of random collection of various products that aren't really related. ..."
The Microsoft VDI Suite starts at $21 per user, per year.,
and more here: http://vbridges.com/wp/?page_id=61