Earlier today Apple released iTunes 10.1, bringing compatibility with AirPlay and support for iOS 4.2.
What’s new in iTunes 10.1
Use AirPlay to instantly and wirelessly stream videos from iTunes to the all-new Apple TV.
Sync with your iPhone, iPad, or iPod touch with iOS 4.2.
Provides a number of important stability and performance improvements.
So far iTunes 10.1 is available for Mac OS X 10.5 and higher and Windows (32-bit and 64 bit), and can be downloaded directly from Apple or through the software updater.