While not a feature rich update, iTunes 10.1 does hold two significant changes. First, the inclusion of AirPlay. This new feature allows you to stream content from your computer to an AirPlay enabled device, like the Apple TV (Version 2). That means if you recently bought Iron Man 2 from the iTunes Store and want to watch it on your big screen TV but don't want to rent it too, just fire up iTunes and your Apple TV and with AirPlay you can watch it on the big screen. AirPlay technology is also coming to iOS devices in the 4.2 update. Second and most import, at least to users of iPads and iPhone 4s, is the ability to sync iTunes with devices running iOS 4.2. As is typical with new updates to the iOS, you will have to upgrade your version of iTunes to this latest one. That means if you are still running iTunes 9, you have no choice but to download this update.
Windows users, there is also a new version of iTunes for Windows out as well. It too is 10.1. Run your Apple Updater or just go to the www.apple.com/itunes and download either the 32 bit version or the 64 bit version.