I've been searching the threads and I think what I wanna say here hasn't been spoken out explicitely yet.
When I tried to make up a possible end of the manga, I started to think what could happen to Sasuke since he is a criminal. I wanted to make a list of his crimes for starters. By then I realized that he did not commit any.
- OK, he joined Orochimaru, but in the end, he killed him. So clearly he did Konoha a favour.
- And he killed Deidara. It is safe to assume that if one of the Konoha shinobis had crossed Deidara's paths, they would have tried to dispose of him, too - as Kakashi and Naruto intended to do during the "Safe-Gaara-Arc".
- He killed (in a way) Itachi, but for all we know, he did not have long to live anyway.
- And he supposedly killed White Zetsu. No blame here.
In short, he killed 3.5 members or former members of Akatsuki.
The only feet-on-the-ground crime Sasuke committed was killing Danzo. But is there really anybody who thinks that any Konoha-citizen will blame him for that? Mister "gimme-as-many-DNA-samples-you-can-muster-to-increase-my-strength" led root, and at least, Jiraiya, Tsunade, Kakashi, Yamato and Nara Shikaku did not trust him. And it's safe to assume that was just the tip of the iceberg. Danzo betrayed Konoha in more than one way: He did not support the Konoha-Nins during Pain's attack, he cooperated with Orochimaru, he sabotaged Yamato's, Naruto's, Sakura's and Sai's mission by giving Sai orders to contact Orochimaru, and there may be more. Sasuke killed a traitor of Konoha.
Right now he is trying to dispose of Kabuchimaru, Mister "I-gave-myself-as-many-DNA-samples-I-could-possibly-muster-to-increase-my-strength-and-use-everybody-so-that-I-can-still-utterly-fail-in-the-end". He makes the Manga way more interesting, but nobody will miss him.
What we can say for sure is that Sasuke is extremely good at failing to kill or at least capture people: He unsuccessfully tried to kidnap Killerbee, and he unsuccessfully attempted to kill Kakashi and Sakura. And I fear that he will also fail to kill Kabuchimaru.
I hypothesize that the question won't be how to redeem Sasuke in the end, but to come up with a good reason why he should need redemption.
The only thing is that I hope Kishi won't try to sell us something like "Sasuka was planning this all along." That would be a bit of a stretch.