I dont think Tobi is Obito
As I've stated before with my last thread, I believe Tobi is Izuna using Obito's body....the manga left with a question whether it truly is Obito with a flashback of him, but I think kakashi will harbor more hatred if his friend's body was being used by someone else.
I believe Izuna found the body and did the Orochimaru transplant since he needed a younger body and it was that of an Uchiha, giving him the ability to awaken the sharingan and use it easier.
There are still too many reasons why it can't be truly Obito since he always talks about how long he's been waiting for revenge, even back when he fought Minato, which was about 2 years after Obito's death and how he also managed to give Minato a hard time considering that Obito died with having hardly any skill.
Also all the knowledge about jutsu, the past, and controlling the Kyuubi....there is just no way it's Obito using that body. Also the fact that Obito still has no clear motive for revenge. The most I could think is that he would have hatred toward kakashi, but Obito gave him his eye out of friendship and wasn't mad when he died.....it has to be someone else.