Apple released iTunes 11.4 Beta 2 for developers. It happened two weeks after the release of the first beta.
Developers who are registered on the Apple Developer Center can download the firmware to your computer and update via iTunes. Can also be updated over the air, if on a smartphone or tablet equipped with a special profile.
About changes in the new version nothing is known. Most likely, the update has corrected mistakes of previous releases, and enhanced security.
In iOS …