I think the fight will go the same way as Hashirama and Madara's, only the end or the result will be different. Remember, Hashirama said that he had to kill his friend to protect the village, and that goal of protecting the village caused him to change, to where he was willing to kill his friend to reach it.
Naruto keeps saying over and over that he'll never change, during the current fight with Tobito, while Tobito keeps telling him everybody changes and turns into someone like him. Either die a hero or live and become trash. So maybe Naruto is going to prove that he'll never change. He also told Sasuke to save up all his hate and take it all out on him, and then they'll both die. And then in the other world they'll finally understand each other. I don't know if that means that Naruto will kill him at the same time. Naruto said "If I die, you die." So maybe what he meant was that Sasuke will die as a consequence.
Also, nearer the beginning of Shippuden, Kurama warned Sasuke DON'T KILL NARUTO, or he'll regret it. So I wonder what he meant by that.
I think the last fight will be pretty rad because all kinds of things will have to come together that have been established pretty early. The Hashirama/Madara fight is pretty cool because it's setting up all kinds of expectations now, because the Naruto/Sasuke fight is going to be very similar, and the climax will be the most exciting, because people are going to wonder the most about the end.