iTunes 9.1 adds three significant pieces of functionality-
Sync with iPad to enjoy your favourite music, movies, TV shows, books and more on the go Organize and sync books you’ve downloaded from iBooks on iPad or added to your iTunes library Rename, rearrange, or remove Genius Mixes
Users with jailbroken iPhones should note that, according to some reports, syncing your handsets with iTunes 9.1 will relock them. This is normally the case with updates, but some users also say they have experienced no problems so do it at your own risk. Update: Blackra1n Fix for iTunes 9.1 has been released. Download BlackBreeze Download iTunes 9.1 for Windows and Mac