Well, I did expect Sasuke to turn good at the end of the manga, but not
this quickly. It does feel like Naruto's efforts may have gone to waste:
It just goes against everything Naruto's character was set up for. His big, over-arching goal was to redeem Sasuke. But Itachi and the Hokages did it. Now Naruto is only indirectly involved. He was the inspiration in Sasuke's redemption, but did not have an actual hand in the redemption.
Poor Naruto didn't even feature in Sasuke's thoughts. It was all about Itachi.
Of course, anything can happen after Madara is taken care of. Like Nate said:
I don't see it being this simple. All Sasuke said was that he wouldn't let his brother and village go to waste. What does that ultimately mean? I thought he'd end up with an Obito-like goal...it sounds good, but it's really not (I don't mean Obito's specific objective). This shouldn't be surprising as Sasuke has his greastest chance to take revenge on Konoha with Naruto not around. Given that Kishi is all but screaming from the mountain tops what the end game is, there was no way Sasuke was going to revert to his original course because even if the First can pull a Madara, the whole village would be witness to him actively tearing it apart and that complicates Kishimoto's ultimate goal.
Also, does anyone think Orochimaru is just going to stand and watch?
Just because nobody wants to see the villages and the sacrifices of shinobi all over the world go to waste, doesn't mean that they'll all be holding hands and skipping over fields of flowers with rainbows in the background. In this fight, everyone (except Madara and Obito) is united by a common aim; they would like to keep the world the way it is, thankyouverymuch. After the dust has settled, everyone could have ideas of their own.
I also don't understand why some people are jumping to conclusions about pairings. When Sasuke was good, did he even have an iota of romantic feeling towards Sakura? Of course not. To date, we have not seen a SINGLE panel of Sasuke thinking of Sakura as more than a comrade, and Naruto has not expressed any romantic feelings for Hinata. Like
kirabook and others have said, NaruSaku has had consistent build-up through the whole of the manga so far with clear development of feelings from both Naruto and Sakura. Naruto still loves Sakura, and Sakura has been questioning herself about what she really feels for both boys. If you look at the whole, it does appear that Sakura just needs a little push, and it may come soon.
If Sakura was simply going to revert to her old Part One fangirling self, then why would Kishi waste all that ink and paper on developing the relationship between Naruto and Sakura?
In fact, I think my biggest disappointment in this chapter was Karin. Yes, she rages over Sasuke stabbing her, but then she easily forgives him. How can she completely trust him again? It's just not realistic at all.
Well, I'm looking forward to Naruto and Minato being reunited.

Like
Baguette said, I think Minato plans to give Naruto the other half of the Kyuubi's chakra, which he sealed within himself when he was taken by the Death God. But, I also want to see reactions from the Konoha [s]11[s] 10 (Poor Neji

) when they find out Naruto is the Yondaime's son. Please,
please, don't make it into an "Oh, we all knew about that" moment.
I'm just going to go with the flow and see what happens next.