One of the things that Xbox Live did well was the friends list. The Xbox One is taking it a step further. Not only can you have friends now, but followers as well. If you're on Twitter, you know how this kind of works.
If you have a ton of friends, you can now find them easier by sorting as well as adding them to your favorites so you can find them faster.
The walk through touches on the Friend feed as well, which gives you a nice snapshot of what everyone's doing currently.