The new iTunes 10.4.1 update is available from System Update and Apple's download page, which lists a 90.26MB Mac Universal Binary package as well as two Windows versions, one for 32-bit editions and one for 64-bit systems.
Apple's update notes for the new release lists the following improvements:
Fixes a problem where the media keys on some third-party keyboards work inconsistently with iTunes
Addresses issues with adding artwork to songs and videos
Resolves an issue which may cause iTunes to become unresponsive when purchasing an HD movie
Fixes a problem where iTunes may take longer than expected to open after waking your Mac from sleep
Addresses issues with VoiceOver support
Apple has separately issued a 10.5 version of iTunes to developers for testing, which incorporates support for syncing with devices running iOS 5.