i got the impression that once he finally met john in the future and got his mission he understood what happened to his brother, and was at peace with it. I can't see him killing john. But he probably will try to mess with cameron. i wonder what thier history is....he said she's a liar and stuff. and cameron said she didn't know what she'd done to him cuz they'd reprogrammed her, but everything shown in the episode was after she was reprogrammed.