Well I still think the idea that Sakura would kill Sasuke to stop Naruto's pain just seems wrong. She would be sacrificing Sasuke so that Naruto could be happy. Granted there was no way in hell should could have beating Sasuke it showed what her intentions were. I'm just glad she didn't follow through with it, otherwise she would have gone from the edge, to rock bottom.
Sakura tried to kill Sasuke because she DOES love him. She agreed with the others that Sasuke must die, and she wanted him to die so that he wouldn't become more evil. Sai said it, saying something along the lines that she wants to kill him so that he wouldn't become more evil. A weird sense of showing how much you love someone, but not as weird as still being in love with someone WHO DOESN'T LOVE YOU BACK.
But she wanted to kill Sasuke herself, not only for their own sake, but mainly for Naruto's. Remember beforehand, Said told Sakura that Naruto loves her, and how the Promise of the Lifetime had given him a great burden. Not only that, the rest of K11 have decided that they believe Sasuke should die. Instead of worrying about Sasuke's current situation, she was more sad that she has indirectly caused Naruto pain and have given him a great burden. She then decided on two options to help lift Naruto's burden: 1) was to confess her love to him, to make it seem as if she was over with Sasuke, meaning that not only does he gets what she thinks he wants (for her to love him), but also doesn't give him a reason to keep the promise anymore (he made the promise for HER). 2) if the first option didn't work, the second option was try to kill Sasuke herself and make Naruto hate her. If Sakura killed Sasuke herself, then his blood will be on her hands, and just her hands. No one else had to kill him, and it wouldn't be Naruto's failure of saving him, it would have just been her decision. Naruto would only hate her, and no one else, this was her trying to repay Naruto for giving him a lifelong burden.
In her mind she had to two option for Naruto: she would either love him or make him hate her. That was her way in trying to replay Naruto for everything he has done for her. For Sasuke it was one option, he needed to die. But now Sakura has hope, Naruto has now given her hope that team 7 may be reunited.