Are you people forgetting Everything Obito taught kakashi? He tought him his ninja way, "Those that break the rules and regulations are scum. But those who abandon their comrades are worse than scum! If I'm going to be called scum either way, I'd rather break the rules! And if that's not being a proper shinobi, then I'll destroy that idea!"
There is no way Tobi=/=Obito. He is completely different as it comes to goals, thoughts, and personality.
However this doesn't mean "wow you nub, yous saw Tobi's Sharingan and Technique is somehow linked to kakashi", He has Obito's sharingan probably, the one that was supposedly crushed one. Tobi had collected a lot of sharingan, probably most of them from the Uchiha massacre, but he had most likely be attempting to gain theme earlier and after the massacre(attempting to gain Shisui's eye from danzo). My thoughts are that one of the Sharingan that tobi had gained was Obito's and saw the potential power in it, therefore he started to use it. Obito was generally a good kid(didn't unlock his sharingan till he was a Chunnin). He was a person who believed in a better future, and left his future in the Hands of Kakashi and his generation.
Tobi Can't be Uchiha Obito, but he MOST LIKELY has Obito's crushed sharingan.