UPDATE: Microsoft have also now confirmed that your Xbox LIVE Gold Membership will carry over to the Xbox One as well.
Microsoft have confirmed that the Xbox One will allow your existing Gamertag, avatar, and all of your hard-earned points for your Gamerscore to be ported over from the Xbox 360.
Your hard earned Gamerscore will port over, so yes you'll take that with you," said UK marketing director Harvey Eagle at an Xbox Reveal event in London today.
"You'll also take your Gamertag, your identity with you. Whilst we're making a much bigger bet on natural identity with the camera, Avatars will also feature as well. All of the gaming identity that you have on Xbox 360 will be there on Xbox One as well."
Well that's a relief. [IGN]