I had installed Windows 7 last week, but my big problem was getting my Blackberry talking to the Mini afterwards. Based on the USB tones, it was losing a connection shortly after establishing one, and the Blackberry Desktop Software could never connect to it. I went back to XP Pro because I occasionally need to tether my phone for data.
Decided to give it another try after hearing the Desktop Manager software does indeed work on Windows 7, and that it could have been my phone.
After reinstalling 7 and the Desktop Manager, I still can't get the two to talk, HOWEVER, that's ok. I was able to get Bluetooth networking & dialup working properly, and in fact it's working better than under XP. My big problem with using Bluetooth for dialup was I kept losing the connection to the phone if the connection goes idle for any amount of time. Under Windows 7, connectivity with Bluetooth tethering is so far darn near perfect.