I stand by my prediction from last week that it's not Obito, but rather either his eye, or his father's eye that Tobi is using. Obito's dad would have been old enough to be Tobi though, that's really not that far of a stretch. Kakashi OBVIOUSLY figured something about him, and Kishi is hinting at the Obito connection probably just to screw with everyone so no one figures out who he really is.
So there you have it, my predictions...Obito's dad(ya never know), or an eye related to them...remember Tobi has all them eyes from him and Itachi's assault on Uchiha...they could have killed Obito's dad during that and now he's using that sharingan. Or he somehow got Obito's supposedly crushed eye. I do not, however I believe it's NOT Obito