Here's my theory.
Rin was killed by the Root (There was a thread where some other poster pointed out that when Obito smashed in one of the Anbu Masks, the head band behind it didn't quite match up with the Hidden Mist symbol, I don't know where that thread is though.) and Obito found out about that (during the fight where he was smashing in faces/masks), hence why he attacked the Leaf Village instead of simply taking the Nine-Tails back home with him.
This fact that the Leaf Village (Root) used Kakashi to take out Rin (their reasoning perhaps: The Root wanted Kakashi to awaken his Sharingan and so decided to engineer a situation that would ensure Kakashi's Sharingan Mangekyo Awakening, although Kakashi was not (or perhaps he was?) aware that he was being used.) drove Obito to believe that no one could be trusted to keep a promise (displayed by Kakashi and the Village) and that this reality was a lost cause. This being his driving motivation to start the "Eye of the Moon" plan.
With that said, Obito probably won't be TNJ'd unless his trust in humanity can be restored. But as things stand, there really is no reason for him to turn. Rin died because of the Roots insane desire to use Kakashi's Sharingan for their own ends, leading me to believe that Obito will not return to the Leaf Village.