Few moments ago Apple released iOS 5.1 firmware for iPhone, iPad and iPod touch for public an now Apple has also released new iTunes version 10.6 for both platforms Windows & Mac OS X.
Apple iTunes 10.6 complete change log:
iTunes 10.6 adds the ability to play 1080p HD movies and TV shows from the iTunes Store.
This release also includes many improvements for iTunes Match, including:
Improved song matching
Improved album artwork handling, downloading, and display
Addresses an issue where songs may skip when playing from iCloud
You can download Apple iTunes 10.6 for Windows and Mac by going to Apple update App on your PC and tehn install Apple iTunes 10.6.