so i’ve already installed three copies of the rtm (release to manufacturing) of windows 7 and it’s working great!  i’ve upgraded one system (32 bit windows vista home premium) and installed two copies of 64 bit so far.  i’ll try to provide as much guidance as i can on any gotchas that i’m aware of or that you might want to consider before taking the plunge.  the windows 7 upgrade from windows vista warned me about deauthorizing my itunes account which i ignored because i didn’t have internet connectivity at the time and sure enough it needed to use another authorization.  i was using avg 8.5 for anti virus on this computer and everything there ran fine (the two 64 bit computers are using forefront).  if you’ve got onecare on any computers, you’ll need to uninstall it before upgrading to windows 7.