The first part of the Madara-Tobi-Obito deal certainly raised many questions and uncertainties. And I'll say it's all Tobi's fault!..
... For having a name so near to that of Obito's --- coincidence or not?...
... For unmasking only the right side of his face --- may be implying that he doesn't have his left eye and, if he really is Obito, gave it to Kakashi...
... And for making Itachi a villain and geting him killed by his own crank head of a brother (oooh, yes, I hate Sasuke with all my otaku heart!)...
But then I also have some things to thank Tobi for...
... Being a genius Sharingan user, a "high-def" Uchiha --- meaning he can't be Obito because Obito was Narutoish and only got to use his Sharingan hours before (or maybe even just minutes) before he died and gave Kakashi his left eye...
... Being a smooth talker that he even managed to convince Itachi to kill the whole Uchiha clan --- Obita was childish and had low self-esteem and I cannot picture him out as the Tobi who can still be cool even when acting the inexperienced partner of Deidara...
... And for directly stating that HE IS UCHIHA MADARA in manga chapter 397:
As for the issue of Tobi's ability to bend time and space, he cannot be Uchiha Obito because of Obito's beginner level use of the Sharingan at his death. There is also the fact that Kakashi and Ren were with him at his last moments. And if Obito was Tobi, who is a great Sharingan user, what would be his reason to act like the clutzy teammate and for dying? I don't think giving an eye away would improve an Uchiha's ability on the Sharingan. From what I understood of Itachi's story about a pair of Uchiha brothers in the past (I think it was Madara and his brother [?] ), they're supposed to take another Uchiha's eyes to achieve their ultimate techniques.
