If there's a season two, the main villain will be played by another former Terminator.
It could probably be Robert Patrick, Kristanna Loken or Jason Clarke (because they, like Gabriel Luna, fought Arnie's Terminator), but we can't rule out Garret Dillahunt or even Summer Glau. Shirley Manson would probably be an outside bet, though.The Brunner family will escape using Luke's ship.
It's basically one big Chekhov's Gun just waiting to be fired, which can work, considering the dire situation our heroes are stuck in at the end of season 1.