I keep posting this but i'll do it again
I think sasuke is going to beat naruto and take him to get the fox sucked out. Then someone...I don't knnow who just yet but i'm thinking maybe everyone who got beat by naruto (neji, kiba, gaara, and the 5th) is going to save him. The 5th is going to heal him while sasuke is fighting off everyone. sasuke will just be about to hand the final blow to someone but thats where Itachi comes in and stops sasuke. everyone will be shocked that Itachi is helping them but the shock will end when Itachi starts to tell sasuke the true story. then both naruto and sasuke will go to kill tobi/madara.
I have 2 endings so you pick which one you like
1. while fighting madara sasuke will get hurt which leads naruto to get mad and kill tobi/madara. sasuke will say his last goodbye and die in naruto's arms
2. naruto hands the final blow and both sasuke and naruto makes there way back to the village