I think the following will unfold:
Madara saw potential in a young uchiha(Obito) which was clueless of the old ways and found the perfect opportunity to have him inherit his goals. Breaking his ties to his village and friends was a must. I believe madara used gengutsu and had Obito witness the only act that would draw him closer, witnessing Rin die.
We have sasuke probably on the way, he will decide what Obito's role. If he joins naruto's side, Kishimoto will have Obito/Madara tandem, more likely having kakashi die and Obito taking his eye.
If sasuke joins Madara, then expect Obito to join kakashi and Naruto, making it possible that Rin's death was in fact a gengutsu.
Kishimoto has been playing with the "two eyes united" theme for some time now, the eyes being Obito's and kakashi's. Next, i see Obito finding out Madara manipulated him and teaming with Kakashi to take him down. Theres definetly a lot of flaws to this route Kishimoto might take.