Sarah and Joe, if there is a pregnancy maybe it won't be clear at once who's the dad...assuming she has a fairly quick rebound affair.
Re Justin...I was wondering if they were going to go the route of all that publicity about the Senator's future brother-in-law leading to Justin being held for ransom when his unit is attacked. Yes, I know it was done on that show about a TV show (not 30 rock, the other one), but why would that stop anyone? And he feels badly if he's rescued because maybe they killed some of the other guys, but not him, to show they were serious---or maybe the unit was attacked just because he was in it (though that would assume that the Taliban follow US politics pretty closely). Of course maybe he's just got a bad case of survivor's guilt. He must also probably have some kind of physical damage if he's coming home.
As for pairing up with his half sister... earlier he commented that she MUST be his sister because even though she was hot he wasn't interested...kind of even before he knew she was his sister there was some kind of psychic resonance (baloney, but he did say something like that). So again they are going to have to rewrite history to go there... and that Rebecca is one sick puppy...first she throws herself at Joe, then at Justin? She must really hate that family and their mom!