Sasuke vs Kakashi fight happens. Naruto shows up. Convinces Sasuke to stop being a bad guy. Sasuke turns. What all the 3rd hokage could not accomplish with Orochimaru, Naruto will accomplish with Sasuke. Note how Sasuke has come close to really doing unforgivable things...he has ALWAYS been stopped by someone. Almost killing Karin, almost killing Sakura etc. Its a sign that Sasuke has room for redemption. It will be Naruto and Sasuke v Madara.