Making NBC look kind of wimpy with its mere nine-episode extension of Knight Rider, Showtime just ordered a fourth and fifth season of its serial-killer drama Dexter. Says network entertainment president Robert Greenblatt: "I thought at best we would attract a devoted cult audience but soon realized that, ironically, this show is so thematically rich and layered with humanity that audiences of all kinds have flocked to it." But, honestly, what else were they going to watch? Have you seen what's on HBO these days? [Broadcasting & Cable]