I think the reason he didn't kill Micah was because I think he's still partly good. I mean he's been doing this whole good-bad-good-bad thing where he switches every four episodes. I wish they'd make up their minds but I guess that's not gonna happen anytime soon. I really didn't like the season finale though............. R.I.P Nathan.... Although I doubt that Gabriel is going to stay like Nathan forever. They always find SOMEWAY to bring Sylar back.
Yeah the very first episode I watched with him in it was his last. That was really Ironinc. Anyway I heard he was sposd to b comin back. Heard it from a friend that was lookin up spoilers for seasn 4. I hope it's true!