The third developer beta version of tvOS 9.2.2 for the fourth-generation Apple TV is now available. Developers can grab the latest beta version from Apple's Developer Downloads page.

tvOS 9.3.3 beta 3 seeded to developers

Apple hasn't made clear what we'll be able to expect with tvOS 9.2.2, but it will likely feature bug fixes and performance improvements, ahead of the much larger release of tvOS 10, which is expected later this year.