I installed the preview on a stock Dell Optiplex 780 with a NVS420. W8 nvidia drivers worked perfectly. W7 Audio drivers from Dell also work. I uninstalled irrelevant apps (for an education environment) and started piling on the software. ANSYS 2015, Matlab, Autodesk suite, etc.. I am impressed and have not had one crash or lock up so far.
I turned on dotNET 3.5 in the same way as windows 8 (but use the install disc not download) and all the redistribs and prerequisites ran first time. Profile copying and image cloning has worked the same as before and local group policy can keep a lid on mods. I'm interested in any thoughts and feedback from similar users.