Sasuke didn't kill Oro, he defeated and trapped him. Oro is basically Sasuke's bitch now. So let's see....Sakura and the old lady killed, who was it? Sasori? The puppet kid. Sasuke defeated and pretty much owns Orochimaru, aanndd, what has Naruto done? He hit a weakened Kakuzu with his ubor new double edged sword. But it wasn't enough to finish him off. Kakashi had to step in and deal the final blow. And Sasuke wasn't a bitch for going after a physically weakened Orochimaru. If that's so, then Naruto is equally a bitch for going after a weakened Kakuzu, which, again, he didn't defeat on his own. Oro was physically weak, that's why he took Sasuke into his mental realm, he knew he'd be stronger there. And Sasuke won that battle with ease.