Nope, I don't think that Naruto will turn his back to Sasuke even if he destroys all Konoha. Naruto wants to become Hokage and he thinks that his first step to accomplish that, is to "get Sasuke back". I believe that the "Naruto shippuden" manga will end exactly as the "Naruto" manga ended. With the fight of Sasuke and Naruto, the fight of two men rather than the fight of two kids.I don't think it will come to an end soon. I do think that the manga will end when the Naruto-Sasuke issue is resolved: either they become friends again (because Sasuke remembers their childhood), or Naruto decides that Sasuke has become an enemy and stops dreaming about him. I really think this because the whole manga and series stress stories about friendship and feelings, with battles between them. I still remember that song: "You are my friend...."