Today At WWDC 2011 Apple previewed iOS 5 & also made iOS 5 Beta 1 available for developers to test their apps on iOS 5. Along with iOS 5 Apple has also released iTunes 10.3 & seeded iTunes 10.5 beta to the developers which is required in order to activate iOS device running iOS 5 beta 1. Also with iTunes 10.5 users can sync their favorite music, apps and more to iOS device running iOS 5 beta.
iTunes 10.5 Beta is only available for Mac and requires Mac OS X 10.5 or later and about 200 MB free space.
If you are registered developer of Apple iOS Dev program then you can download iOS 5 Beta and iTunes 10.5 Beta today. Access below link to download iTunes 10.5 Beta.