“Today we’re rolling out several of the new social and entertainment features we shared earlier this week, in addition to a few unannounced features, to the members previewing new system updates. Your input on feedback.xbox.com plays a big role in shaping these updates, which will roll out to all Xbox One owners in the coming months.”
(see link for video overview and more details)
tl;dr:
Party App reorganized with Party Leader
Friends section reorganized with Gamerscore leaderboard
Media Player - from USB or network connected home server (formats listed)
Digital TV Tuner - Europe first, retail in October
Stream TV to Smartglass
Boot to TV
Live TV Miniguide in OneGuide markets
Smartglass Actvity Feed expanded
“Xbox On” markets expanded
Country expansion - 29 new markets
Multiple GameDVR Deletes
Save Avatar Gamerpic to OneDrive
Settings reorganized
Bandwidth Usage Display