I was talking to a member on NF who has been there since 2004!! He said people theorized he was Obito since the spoilers of his first appearance and his offical debut in ch.280 :lol. The clues were the placement of Tobi's eyehole, hair and personality I didn't know until ch. 599. I started getting convinced he was Obito when it was revealed he had the same MS as Kakashi.