iTunes 9.2.1 provides a number of important bug fixes, including:
? Addresses minor issues with dragging and dropping items
? Addresses a performance issue when first syncing to some devices with iTunes 9.2
? Addresses an issue upgrading to iOS 4 on an iPhone or iPod touch with encrypted back-ups
? Addresses other issues that improve stability and performance
iTunes 9.2 comes with several new features and improvements, including:
? Sync with iPhone 4 to enjoy your favorite music, movies, TV shows, books and more on-the-go
? Sync and read books with iPhone or iPod touch with iOS 4 and iBooks 1.1
? Organize and sync PDF documents as books. Read PDFs with iBooks 1.1 on iPad and any iPhone or iPod touch with iOS 4
? Organize your apps on your iOS 4 home screens into folders using iTunes
? Faster back-ups while syncing an iPhone or iPod touch with iOS 4
? Album artwork improvements make artwork appear more quickly when exploring your library
For information on the security content of this update, please visit:
http://support.apple.com/kb/HT1222 
