The news comes courtesy of the company's UK marketing director Harvey Eagle, speaking at a screening of the Xbox Reveal event in London today. "Your hard-earned Gamerscore will port over, so yes you'll take that with you," he said.
"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."
What you won't be able to take with you is any Xbox Live Arcade purchases, as the Xbox One will not be in any way backwards compatible. However, entertainment content that you've purchased, such as movies, will carry over.