Today, Apple seeded the tenth beta build of tvOS 11 to developers, bringing the build string to 15J5380a. There are no new front-facing features; instead, it focuses on fixes with a GM seed right around the corner.
Indeed, Apple began sending out invitations last week for an event on September 12, where it's expected to launch a trio of new iPhones, an Apple Watch Series 3 that supports 4G LTE, and an Apple TV that supports 4K and HDR. Afterward, the firm will release the GM seeds for iOS 11, macOS 10.13 High Sierra, watchOS 4, and tvOS 11.
The new build still has issues with some third-party apps, like Sling TV and FoxNow, although at this point it's likely up to the developer to fix them. The rest of the known issues seem to apply to the developer end of things.
tvOS 11 isn't going to bring many new features to the platform; in fact, it didn't even make the keynote for WWDC, with Apple holding a separate session a couple of days later.