Marge Piercy explored both utopian and dystopian futures in Woman On The Edge Of Time, and she explained the difference between the two modes of imagining the future, in a speech at the University of New Mexico.
Said Piercy, the impulse that drives us to imagine a utopian future is the fact that "You have to have a way of imagining a society you want you or your children to be able to live in." On the other hand, dystopian fiction asks the question: "If this goes on, what is going to happen?"
In other words, one is more based on our hopes for our children's future. The other is based on our actual observations about the way the world is, and how it appears to be developing. [UNM Today]