If this weeks spoilers are correct, then karin is still alive, this leaves us some things that might happen..
1- Sasuke ends killing karin,without caring that sakura is there(why would he care anyway?),
2.Sakura prevents sasuke from killing her,
3-Sakura changes his mind about sasuke seeing how he treated his companions,
4.Karin somehow manages to warn sakura about sasuke and his cold heart full of revenge and nothing else.
5.Sakura blind from love, deos not understand the circumstances of the situation and does not realize that sasuke is being manipulated by hatred and pulled by madara´s strings without him noticing it; manages to convince sasuke from letting her walk by his side.Sasuke either takes adantage of Sakura´s healing abilities or he refuses her help and sends her back to Naruto.
Now, madara does not know yet that kisame has failed in his mission so he MIGHT assume that Kisame succeded and will go for naruto, taking advantage of the situation, he will realize that konoha does not have a hokage now so he might also asume that kakashi will be the new hokage, either way, they will go to konoha and find the elders , once they go there and since once sasuke´s goal is complete he will go after him, he will make sure he takes naruto first , since without sasuke´s help he wont be able to take naruto hostage since there arent members in akatsuki.
So what do you think, too crazy?