IMO, you can always have a master VHD image that contains system and commonly used programs, then put your development tools and such in a secondary VHD. With ProcMon and "Undo disk" feature of VM, you can extract the list of registry values/files installing on the system, so you can put them in seperate folder and got them patched to the system on "System Start" schedule.
Requires lots of work on your behalf, but certainly could be done.
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Regarding drivers... could you even be sure that the "isolation" related system service are loaded when the driver is loading? I believe the current isolation model is depending on winlogon, but by the time it's loaded it could be too late for certain drivers...
Also, from documentation it seems driver's Unload() is not required to be implemented except for WDM drivers.
