With the iTunes 8.1 update, you can now sync with the new iPod shuffle, take iTunes DJ requests from friends, rip CDs at iTunes Plus quality and use Genius with movies and TV shows. There are other features, like bugfixes and stability updates, but you can read up on that yourself. [Apple via MacRumors]
iTunes 8.1 is now faster and more responsive. You will enjoy noticeable improvements when working with large libraries, browsing the iTunes Store, preparing to sync with iPod or iPhone, and optimizing photos for syncing.
In addition, iTunes 8.1 provides many other improvements and bug fixes, including:
• Supports syncing with iPod shuffle (3rd generation).
• Allows friends to request songs for iTunes DJ.
• Adds Genius sidebar for your Movies and TV Shows.
• Improves performance when downloading iTunes Plus songs.
• Provides AutoFill for manually managed iPods.
• Allows CDs to be imported at the same sound quality as iTunes Plus.
• Includes many accessibility improvements.
• Allows iTunes U and the iTunes Store to be disabled separately using Parental Controls.