We had a science fiction panel at the latest World Future Society and discussed Neal Stephenson's comments at length. I personally believe that dystopia and utopia both have a functional role in the genre. Utopia (done well) gives us something to strive for and actively work to achieve and dystopia (done well) teaches us what to avoid and actively work to prevent. But overall I agree with the notion that there is not enough imaginative optimistic science fiction, and that this is a problem. So maybe science fiction needs to go back to its first roots. The first works of science fiction were mostly works about how human beings could reach the stars (i.e., Somnium - 1608) and generate infinite possibility (i.e., The New Atlantis - 1624).