Layering technologies

If one is set on the VDI route, I would suggest exploring layering technology as a fit to bridge the gap of need/capability in Windows. Unidesk's technology (now owned by Citrix) is a great example of this capability. These technologies treat the OS image as a layer upon which registry changes, applications, documents, and so on can all be layered into the image before it is presented to the end user.

This thins the data that is relevant to the user considerably when we consider things such as backups, data integrity, and so forth. It also allows enterprises the agility to modify or remove/add applications quickly to a user or group of users with little of the traditional imaging overhead common to VDI.