This is a pre-release version of tvOS 9.1 for the new Apple TV. Devices updated to tvOS 9.1 can not be restored to earlier versions of tvOS.
tvOS SDK 9.1 beta 1 provides support for developing tvOS apps. It’s packaged with a complete set of Xcode tools, compilers, and frameworks for creating apps for tvOS. These tools include the Xcode IDE and the Instruments analysis tool, among many others. This version of tvOS is intended for installation only on devices registered with the Apple Developer Program. Attempting to install this version of tvOS in an unauthorized manner could put your device in an unusable state.
Developers can download the beta from the link below...