The Ending To The Manga.
Do you all think the Manga is going to end when Madara is dead? I think not. It didn't when Orochimaru was killed, and I remember back in the days before Shipuuden, everyone thought it would when he was dead, because he was the number on villain. There a chance that Sasuke will take either Naruto's place, and the Manga will end, or there's a chance he'll take Madara's place, and the Manga will continue again.
Don't forget that the battle between Naruto, and Sasuke is foretold in legend essentially. It's pretty much set in stone that they will do battle again, and again until one of them, or both of them is dead. I believe that will be the end of the Manga.
It's been said that there can be no Peace in the Ninja World, and that the days of the Shinobi must end before Peace finally reigns over the land. I believe with Naruto, and Sasuke's death in their final fight, The world will realize that things need to change, that no more people need to give die in the name of peace, because peace will only come when they decide to quit fighting.
A major clue to this fact is Naruto forgiving Nagato, after all that Nagato did with Pein. Fighting only breeds more hatred, that's a fact. I believe that fighting, and hatred ends with Naruto & Sasuke. It started with the 1st Hokage & Madara so many years ago, therefore it will end with their descendants. And so, the world will learn to forgive each other for the past, and move on into a new chapter. (A Chapter which I doubt will include the Manga continuing, Lol.)