During an 'Ask Microsoft Anything' event, Marc Whitten (Corporate Vice President for Xbox) revealed a few things about how profiles on Xbox One will work amonst other things.
Twitter like friend/following system
It was announced a while ago that the Xbox One would allow an extended cap on the amount of friends you could add - raised from 100 to 1000. However in addition to this, there will also be a Twitter-esque following system which will allow you to have Unlimited Followers as well as the ability to Follow other gamers. By following a gamer you will get information based on their activity on Xbox Live (such as what games they are playing) - you can also prioritise which gamers feeds are more predominant in your friends feed.
At launch, the Xbox One will have a selection of 300 1080p gamerpics for you to choose from. The gamerpics, examples of which can be seen below via IGN, will show information about you such as Gamertag, Gamerscore, Tenure information, Reputation (whether you are a good/bad player) and your following/follower stats. You'll also be able to create full-body poses of your Avatar to use as a gamerpic if you so wish. Unfortunately though, there is no plan to allow custom images to be uploaded for use.
Scanning of QR Codes
The ability for the Kinect to scan QR codes in order to redeem content such as Map Packs, Avatar Gear and Gold Subscriptions.
Multiple sign-in's on one Profile across platforms
The ability to be signed into an Xbox One and an Xbox 360 using the same profile at the same time - however the profile cannot be signed into two of the same devices at the same time - as is standard currently on Xbox 360.
Reputation will not be carried over from the Xbox 360 meaning that all members will be in good-standing when they cross over. The only exception to this will be a few gamers who have recently had major infractions against their accounts which will be automatically categorized into the 'needs work- category - meaning they have the chance to prove they can be good on Xbox Live.You can see all of this information and more over at IGN's website.