Do anyone consider Sasuke attack Karin is the same as Naruto(Kyuubi 4 tail) attack Sakura, we found out that Mangekyou can influence the user to become more darker. maybe when Sasuke and Karin meet again, Sasuke might have some regret what he done to her.
Most people doesn't really understand Sasuke.
I hear sometimes that he doesn't care about Sakura because he tried to kill him. But this is not true, especially when you know today why he's acting like this.
It's a curse.
If Sasuke really doesn't care about Sakura, than it's the same for Naruto. Cause he tried to kill him in first part, remember, the Chidori in Naruto's heart with an evil expression ?
Result : We see Sasuke always caring about Naruto deep inside his heart in second part (Naruto's bridge scene, Amaterasu against Killer Bee, encounter with team 7)
Sasuke just lie to himself, he tries to destroy the bonds he has with Naruto, Sakura and Kakashi because it hurts him deep inside his heart. He's not 100% evil yet, he just needs that light that Gaara was talking about with him at the Gokage reunion.
I even think it's the same for Madara and Obito. Madara wil probably vanish after encounter with Hashirama who will save him from darkness.
Obito will probably be saved by Kakashi and Naruto. He already showed some weaknesses.
So, I think he probably regrets what he did too Karin, otherwise, it doesn't this make sense what we saw before that event.
The guy took risks against Killer Bee to save her twice :


He doesn't even listen at positive suggestion of Juugo, he just stay there, only for saving
Karin.
And a few weeks later, he tries to kill her, for an uknown reason (and SasuSaku fans were confirming that he doesn't care about her)... until Hashirama's and Tobirama's excplanation about Uchiha's curse.
The "Sasuke doesn't cares about his friends" doesn't work anymore.
Even Sakura, he cares about her, of course, I don't see him in love with her, but he has the same bond as every team 7 member has with her.
They are family.But his family is now growing, he encouters new teammates, that he makes him think about that same team 7 (what makes him decide to use Amaterasu to save them) : Karin, Juugo and Suigetsu, who doens't hesitate anymore to give their life for him.
Suigetsu who didn't care about him in the beginning is now doing everything for him. For Juugo, Sasuke is everything to him, and for Karin, she's just madly in love with before part 2 began.
He realized that after Killer Bee fight, but the curse took advantage in Gokage's reunion.
Today, Sasuke seems to be calm, returning to his trueself, even Orochimaru doesn't reconize him anymore.
When Karin will meet Sasuke again, I think that he will apologize for what he did.
Of course Karin will have an explanation about "why he did this to her". She probably knew that he wasn't himself, but she doesn't know yet it is because of the Uchiha curse.
Maybe that this will also gives Karin the opportunity to make her confession ?
We definitely have to know what happened between those two in Orochimaru's hideout. I think it could give us some hints for a futur pairing.
Yes I believe in SasuKarin. I believe even more than before when Kishimoto confirmed that she was an Uzumaki.
Hope we will see her soon.