Xbox One users are now testing out the beta for the latest update to the Xbox One user interface. This update brings about more Fluent Design principles to the Xbox One experience. It is also the update that allows you to customize your Home.
Customize Your Home:

This update also includes streamlined tab flyouts for easier navigation. Microsoft has also expanded on the social aspect of the platform and have included some nice updates for the Windows 10 Game Bar. You can read all about these changes at Xbox.com. The update should leave beta some time this Fall and will then be released to everyone.