The Future You Imagine is the Future You Get

In the past, dystopian fiction has served as a kind of modern-day cautionary fable. But what's the other side of the coin? How do we tell tales of futures that we can aspire to, rather than ones that we warn against? What are we working towards, and how do we avoid the pitfalls of premature nostalgia and the tendency to excessively homogenize our utopias?