The UI runs fast, anyone can log in from anywhere (the system can recognize people through their faces and voices) and their profile data will download from the cloud to the local system and the system can run four apps and a game simultaneously. Also, the Xbone via Kinect can control anything which uses a remote in the living room no matter where they are placed since it saturates everything with IR beams (even bouncing beams off of walls). You can have 1000 friends and an unlimited number of followers. In 2013 you can only post videos to XBL but in 2014 you'll be able to post to places like Facebook and Youtube. Pictures and detailed impressions at the link.
Working with full production Xbox One hardware, we saw the UI running on what was essentially a final hardware unit. Content was being populated in real time from Microsoft HQ. They ran full test code in front of us, so no canned demos here.
Penella signed into the dash by just waving his hand. Actually, work went on to do so in the background before he even did that, as the Kinect was already seeing and trying to recognize everyone in the room. Waving was more of a confirmation that he was the one that wanted to sign in. From that confirmation, Xbox One pulls down all of Penella's settings, just as he had set up in Redmond, including all of his saved games, apps, and settings.
This is how it works on any Xbox One. Using someone else's Xbox 360 to sign in was next to impossible with required recovery work. No more of that now. Just pop in your ID and it'll immediately start pulling down your content and settings from the cloud. This works from anywhere in the world, too.
Speaking of signing in, Xbox One is friendly to multiple users. The previous systems were not. Now, six users can sign in at one time. Kinect is always watching to know who is in the lead in this case. It sees who is holding the controller and recognizes your voice among others. You could be in a room with five other people logged in and call out to launch a game, and it would do so with your settings and saves intact.
Game capture is pretty slick. We saw a marble maze game get instant capture of the last 30 seconds of buffered frames from a simple voice command. Xbox One's Upload Studio had a 720p 30fps clip waiting immediately after. Users can quickly edit, save, or share this clip with further commands. Another voice command can have you back in the game just as quickly.
Penella says that these clips will only be able to be shared on Xbox Live at launch. They'll have social sites like YouTube and Facebook set up for sharing by next year.