From my interview with Moira Kirland, Supervising Producer on Medium
Our best shows are when we completely subvert the audience's expectations, and we do that consciously. For example, in "Coming Soon," Alison has a dream that there's a threatening man in her house. Then she sees the man from her dream. He's a witness to a crime, a Good Samaritan, doing his civic duty. Apparently a nice guy. But when she shakes his hand she's sure he's a serial killer. And the audience is thinking: this is the one where Alison has to convince everyone he's a serial killer, and no one will believe her, and he'll kidnap her and she'll have to escape. But the way we play it out, in Act Three, she realizes all her visions are of events taking place in the future. He hasn't started killing yet. So in Act Four, all she can do is find the girl who will be her first victim and say, "You're gonna meet this guy. Don't get in the car with him. If he tries to get you to do it, fight him." And that's all she can do. ... What we try to do is to set up the paradigm and then alter it. In Desperate Housewives and Lost, you go, I think I know where that's going. But you're wrong. And that's more satisfying. It's always satisfying to be surprised.
CRAFTY TV WRITING: But sometimes you want to be right about where it's going, don't you?
MK: There are fewer shows now like Murder, She Wrote or Touched by an Angel that allow you to see clearly where we're going. But sometimes you want that. A nice quiet hour of comforting, unchallenging TV. It's like macaroni and cheese. It's not that exciting, but you know what it's going to be, and that's comforting. Law & Order I enjoy but I'm not surprised. You know the first person they interview is not the killer. You get the template. Or they have guest stars. On this one show, the fiancée was Kelly Martin, and she goes away after the first act. Of course she did it. She's got to play her big thing in the fourth act. You're not going to have Kelly Martin on the show and she didn't do it. Sometimes you don't want to work that hard. It's a cool medium, not a hot one. It does everything for you.