I feel like, for the climax of this arc to happen, naruto and bee must get captured because it kind of keeps the bijuu underwraps. Minato, i think, will definitely transfer his half of the chakra to naruto in some ways. Kakashi will get out of that dimension, and I want it to be with what happen this past chapter (639 ending scene). As far as Naruto vs. Sasuke, I feel like both will need some common ground. Both Naruto and Sasuke will probably gain some upgrades.
How I see it play out:
Minato's attack will not make it in time. Madara vs. Hashirama pans out. Naruto and Sasuke are about to get hit by Obito's attack and right before it hits, Madara plays his trump card and takes control. Also, in that moment, Kakashi comes out of kamui and absorbs that blast.The kages arrive and see what is happening and join in. Orochimaru meanwhile goes back to kabuto's location and experiments with what he has become and tries to gain his power and keep it hidden ( like how he did with the zetsu and "gaining" control over hashirama's cells). Bee and Naruto get captured, Bee gets the 8 tails extracted while naruto continues to struggle to stay alive but ultimately gets the 9 tails extracted. The bijuu is then complete and Madara unleashes the moon's eye plan. The Kages and Shinobi alliance start to panic and fight back. In that critical time, Orochimaru shows up with his new power and uses justu(s) that help (possibly revive other past kages/ people). They try to get naruto and bee to come back and revive them, but leads to failure. Minato at some point transfers his half of the chakra into naruto and he is revived. Kakashi is on the brink of collapsing, Sakura heals him. Karin goes to Sasuke and helps him and then goes with orochimaru and flees with them. Sai is continuing his suspicion upon Sasuke and does some surviellance upon orochimaru and them, and follows them. Sai hears what sasuke's true intentions are, and also what orochimaru is concotting and goes back to report to the others. This is when Naruto vs. Sasuke will happen but will be postponed because of the bijuu. After the bijuu is dealt with, naruto will gain sage of six paths like abilities when both halves of the chakra are one. Naruto vs. Sasuke will continue. Orochimaru's plan now is underway, and begins to happen. Madara and Hashirama continue to battle it out.
sorry for long response :c but thats as much as i see pan out