Apple has just released a new update for iTunes, bringing the version up to 10.4. The update brings enhanced performance, support for Lion’s Full-Screen App mode, and will run in native 64-bit under OS X Lion.
The update is available now via Software Update on your Mac, or through Apple’s iTunes download page online. From the release notes:
You can now use iTunes with OS X Lion’s new Full-Screen App capability, which allows you to use iTunes and other apps without distractions. Navigate between all your full-screen apps with a simple gesture.
It’s unclear whether or not this is safe for jailbreakers, so if you require a jailbroken iOS device, wait until you receive further confirmation before hitting the update button.