The tvOS 10.2 update can be downloaded on the fourth-generation Apple TV using the Settings app. Go to System --> Software Update to install. For those who have automatic software updates turned on, the Apple TV will be upgraded to tvOS 10.2 automatically.
According to Apple's beta release notes, tvOS 10.2 introduces improved scrolling behavior, allowing tvOS users to scroll through large lists of information more quickly. A longer swipe on the Siri remote activates the new scrolling mode, and a swipe on the right side of the remote allows users to navigate specific indexes.
While Apple's release information only focused on the new scrolling mode, the update also likely includes other small feature tweaks under-the-hood bug fixes and performance improvements.