There has been a lot of press about the leaked Windows 7 RC. For the most part, the press and bloggers have been extremely positive.
One very minor but significant tweak that I’ve found useful as an IT Pro has been full path display in the address bar. In Vista and Windows 7 Beta looked like the image below by default and would require a click on the address bar to show the full path. With Windows 7 RC, Microsoft has rightly defaulted, in my honest opinion, to show the full path all the time. Windows 7 RC has tons of more tweaks. A good article to read especially if you’re waiting for the official RC release is this Computer World article.