The one that really has me going 'What were they thinking?' in terms of the premise and how they'll be able to continue on for very long is Hostages. The doctor's family were all horrible people and if she let them die I wouldn't blame her. The whole 'is he good, or is he bad' about Dylan McDermott's character is interesting, for a little while at least. But how they'll pull this off for a whole season, let alone longer, I have no idea
My understanding with Hostages is that it's only 15 episodes and then it's done. If all 15 episodes are already shot, and they know it's over I doubt it'll get cancelled unless the ratings are horrible, and even then they can finish it on Saturday nights. Of course Under the Dome was supposed to be only one season and some genius ordered a 2nd season, so who know what will really happen.