Apple released the latest iterations of its operating systems for the Apple TV and Watch today, tvOS 10.1 and watchOS 3.1.1. As the version numbers indicate, the Apple TV update is minor, but watchOS 3.1.1 is a bug fix and stability update, which means that there won't be any new front-facing features.
As for tvOS 10.1, the headlining feature is the new TV app, which the company announced back in October. Also available on iOS, it's meant to be a hub for all of your video services and content; however, Netflix is currently not supported.
In fact, the app launched today on iOS today as well, with version 10.2. Other features in the update include support for Unicode 9 emojis, new wallpaper, new camera settings, and more.
The only one of Apple's operating systems that didn't get an update today was macOS Sierra. Version 10.12.2 is still on beta 6, and it's likely that the final version will be released this week.
To update your Apple Watch, open the app on your iPhone and go to General -> Software Update. For the Apple TV, you'll find those settings under System, rather than General.