Will it have custom avatars that we can upload or a set of avatars we can pick from? is it going to be available to everyone or just people who were registered here?
Everyone can have avatars, but due to a sponsorship deal with School Boy Records / Scooter Braun you will only be able to choose stock avatars from artists that he manages / are on his record label such as Justin Bieber, Psy, Ariana Grande, Carly Rae Jepsen and The Wanted.
Srsy, you'll probably be able to upload anything you want that is sfw and not a gif.