A while ago a friend showed off the Mac version to me for cleaning his iTunes library - glad that there is a Windows version now.
beaTunes has a feature called library inspection, which goes through your library and finds different spellings in your artist names, genres etc. It then offers to bulk correct them. Pretty d*&n cool! Especially when you have a ton of songs. Cleaned up my whole library.
The BPM analysis takes a while, but so far the results were pretty accurate (except for the usual doubling). I'm not a DJ, so I don't care too much about it. However, for finding matching songs for new playlists, it is actually quite useful.