OMG...Even if sasuke wanted to kill him, he probably couldn't have. And didn't know how to use ametarasu. Also I think sasuke can be called overpowered in some ways, basically he was given some of the most powerful techs and some of his techs are almost unavoidable. It's good he doesn't have the curse seal anymore...Plus he has the (mangekyou) sharingan, which pretty much made him what he is now.
Kinda off-topic...
Of course sasuke has skill, but that doesn't assure him a win over others. Naruto is probably much faster than Sasuke now with Sage mode. And if you recall back to fight between naruto and sasuke at the end of part 1, i don't recall sasuke's speed giving much advantage to him... it's looked like naruto was too fast for him even 1-tail form. And we don't know for sure if sasuke can actually control the kyuubi, maybe surpress it, but what if naruto wasnted to use it's power. And if that wouldn't work, naruto has sage mode, which is absolute kick-ass. whilst sasuke has the over-powered sharingan.
Don't keep giving the BS about if naruto didn't have this, or sasuke wanted to do this. Coz truth be told, killer bee owned his @$$. You can't guarantee a win just because of one tech, which has already been proven to have not worked.