DO NOT CONTINUE IF YOU HAVE NOT READ CHAPTER 599!
For the past few weeks we have all been waiting and watching to see who the masked man of Tobi is. And now with a heavy heart I must do the one thing that I hate doing in life. Admitting I was wrong. Unless somehow it is what I think it is and it really isn't the person who was revealed as Tobi, then Kishimoto has some major explaining to do.
Tobi has been revealed on the last page of chapter 599 that he is in fact, Obito Uchiha. If the title of the chapter didn't already give it away (although I was under the influence that Kishimoto was trolling us again and giving us Kakashi's memories and such) yes, it is the former teammate of Kakashi whom everyone presumed was dead.
So my fellow members of the site, how do you think Obito escaped? Why has he turned to the dark side? Is this really Obito's spirit inside of him? Is Madara just controlling his body? Alas we have to wait until next week to find out.
Where Kishimoto will probably take us back to Sasuke and Orochimaru again... ._.