naruto might become hokage before the series actually ends, and he will have different tasks and challenges to reorganise the Shinobi world. Then i think it will end
For Naruto to become Hokage, Kakashi and Shikamaru will have to die first.
that's why i think after the akasuki arc there will be a root/civil war arc that will kill off a lot of characters that will boost naruto to hokage. when he becomes hokage the series is pretty much over though, since that's been his entire focus from the start, basicly he will end the civil war and become hokage and you'll get the "peaceful happy ever after" end in some ways...
Sasuke will hide somewhere and Sakura will try to go with him. Naruto will continue his training to become hokage Hinata will be helping him, Kakashi will grow old Tsunade will do everything to stop her oldeness, Neji will be married, Ino will fall in love with Shikamaru . Sai will try to find Sakura , Temari will stick with Shikamaru, Kiba will find himself a girl ,Shino...umm will live, Itachi will still be alive and there will be a war coming up and thats the way it will end