In an interview with the English newspaper The Guardian, Cory Doctorow explains why he's not interested in predicting the future using science fiction, but instead wants to influence the future. Here's his killer quote:
"I'm a presentist. All science fiction writers, whether they admit it or not, are writing metaphorically about the present. To extrapolate the future is really to comment on the now."
All in all, a fascinating interview. Check it out.