I've recently been reading Nick Bostrom's book Superintelligence and must admit it stuck with me. It may well seem a tad abstract to us who are new to thinking about such matters, but highly stimulating and thought-provoking.
The main point is driven home thoroughly: We should be talking more about artificial intelligence! Because its arrival might be just around the corner and it has the potential to mark a crossroads for our future, the choices being really really bad or really really fantastically good.
I am currently half-way through Olle Häggström's Here Be Dragons which covers related but broader toptics of near-future technologies.