I think most of you are forgetting that even if Black Zetsu does succeed and able to get the rinnegan out of Obito, it won't serve Madara any purpose, unless all Uchiha is qualified super surgeon and can perform eye transplants and be healed in less time it takes to throw a shuriken.
[Prediction]: All these events are going on so fast. Something tells me Madara is going to call a break. When he finally receives his eyesight. He is going to do something badass and say, "Instead of everyone dieing, why don't the strongest shinobis come and face me instead." Something like that.
If you think about it Naruto has been fighting for an extremely long time, Naruto vs Jinuuriki, Naruto vs Tobi, Naruto vs Gedo, Naruto vs Juubi, Naruto vs Obitio. There has to be a break at some point for rest and damage control.
[Prediction]: All these events are going on so fast. Something tells me Madara is going to call a break. When he finally receives his eyesight. He is going to do something badass and say, "Instead of everyone dieing, why don't the strongest shinobis come and face me instead." Something like that.
If you think about it Naruto has been fighting for an extremely long time, Naruto vs Jinuuriki, Naruto vs Tobi, Naruto vs Gedo, Naruto vs Juubi, Naruto vs Obitio. There has to be a break at some point for rest and damage control.