I've been back and forth with myself on this one, but in my in-dev rogue-like, I was planning on a pretty detailed story, with certain in game events being dictated as well.
I've noticed that many rogue-likes don't have plots, they usually have, "Your god wants you to get the Amulet" stories. At first I didn't understand this, but I think I have it figured out: Once people know the plot, they probably won't want to play it over and over again. I mean, how many times have you replayed those big shot games, like Call of Duty, or Halo, that have predefined stories and everything? I don't want my game to become a "one-and-done" type of deal.
Vote, but please add your $.02 below as well.