iTunes 10.1 Beta has also been released today alongside iOS 4.2 Beta 2. Again, this release is currently meant for developers only, running both Windows and Mac. Except for the support of the new wireless printing feature in iOS, there is seems to be nothing new in this release.
I am currently testing it out. Will report back if I find something new. In the meantime, if you have developer account, you can grab your copy of iTunes 10.1 Beta for Windows or Mac using the download link given below.
Download iTunes 10.1 Beta for Windows and Mac [Developers Only]