Apple has released iTunes 10.5.3 for Mac and Windows. As of this writing, it's available from Apple's site, but not Software Update.

As noted by MacStories, the new version adds support for synchronizing the iBooks 2-savvy textbook format announced during today's education event.

It's been an exciting day for Apple fans, especially those in education, as the company has released a new version of iBooks, a full-on textbook initiative and all-new apps iBooks Author and iTunes U.