Personally, I think there's a strong chance Naruto and Sasuke will both die in the end. Sasuke will be redeemed by his actions in the final battle (after losing to Naruto prior to that), but I don't see their bloodlines continuing beyond them. I think a major thing Kishi's been getting at, especially recently, is that the Rikudou left behind Ninjutsu, entrusted to his two bloodlines, to leave his protection help humanity mature. However, the Ninjutsu system and the existence of such powerful techniques is now simply perpetuating hatred, and the "bad guys" are all scrambling to collect all the pieces of what the Rikudou left behind. Rather than being the hero's Rinnegan facing the evil Juubi, it is now only Naruto, a Jinchuuriki, who is capable of fending off evil Doujutsu users and protecting humanity. Things have come full circle; together, Naruto and Sasuke have the powers of both halves of the Rikudou Sage, and it is their job to end the cycle and perish with Tobi/Madara, without leaving behind their powers for others to collect.

I'd like a happier ending, too. However, a major theme in this manga is that it's not how a Shinobi lives, but how he/she dies that is important. In my opinion, it almost would feel incomplete if Naruto himself didn't make an equally heroic sacrifice.