"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
Apple Releases Third Beta of tvOS 9.1 to Developers
The third tvOS beta is available as an over-the-air update to those who have installed the first two betas. Installing an initial tvOS beta is a more involved process than installing a beta update for iOS or OS X. The update requires the Apple TV to be connected to a computer with a USB-C to USB-A cable, with the software downloaded and installed via iTunes.
We don't yet know exactly what is included in the new version of tvOS, as most changes thus far appear to be under-the-hood updates. Apple's release notes for the update include references to networking and scrolling tweaks, and it's likely tvOS 9.1 will include fixes for bugs and issues that have been discovered in the software since the Apple TV's official launch. We will include any other external facing changes below.
tvOS 9.1 will mark the first significant update to tvOS and the second update to the operating system. The first tvOS update, tvOS 9.0.1, was released to the public on November 9.