I installed Windows 7 last week. All seems to have gone smoothly (so far). I was advised by the Upgrade Advisor software to uninstall iTunes first, so I did that. After the upgrade completed I reinstalled iTunes. This failed a couple of times until I ran the install executable “as Administrator”.
My graphics card driver needed an upgrade – also identified by the the Upgrade Advisor – so I downloaded and installed the latest one. This said that it was not certified for Windows 7 but it seems to work fine.
My Printer (Lexmark 4650) stopped working too. I downloaded the new drivers but these made no difference. So I uninstalled it, and the full Lexmark suite, rebooted and then re-installed. After I had put in the wireless network key it was running just fine again. I had to connect it via USB as when doing the first install for the software.
Everything else seems to run fine. Sleep mode is quicker both to sleep and to wake again. The wife likes the “themes” used for screen wall paper. We are using the Great Britain set at the moment. It cycles between Tower Bridge, Stonehenge, The cliffs of Dover, Tintagel castle, etc.