For anyone interested in making radio apps for the new Apple TV, I've created a beta version of RadioKit that is compatible with the current Apple TV beta (tvOS 9.0). Apple TV uses different library images than iOS, so I needed to create a separate RadioKit library specifically for Apple TV. You can't just use the existing iOS version of RadioKit - it is not binary compatible with Apple TV.
If you want to try it out, the library is here:
http://www.stormyprods.com/Libs/RadioKitAppleTv.zip
It uses the same API methods and names as the version of RadioKit for iOS.
I am currently working on putting together a sample Xcode project for Apple TV which demonstrates using the SDK. I'll followup once I have it complete.