So far the biggest issue is printer drivers deployed through a Win2K3 server (32-bit), while testing Windows 7 64-bit. The main culprit seems to be Dell Printers. We have Dell models in the 1700 Series. We also have some HP printers 2035's that have no issues. The drivers have to be installed locally, for the Dell's. Outside of that, not too many issues I can report.
We are a small, but, fierce shop around 200 to 300 desktops/laptops. We will beginning our application testing on a vm.
--David