People should read Kaczynski's manifesto. It's rough at parts, but it's really an interesting perspective.
http://www.washingtonpost.com/wp-srv/national/longterm/unabo...
Why is future optimistic by default? By the way humanity is progressing, do you see any reason for hope? Do you disagree that we are in a technological runaway?
If we're optimistic and correct, we're building the things that will be useful in the future. We know we have to get off the planet to survive as a species, so we have to hope that we can do so.
If we're optimistic and wrong, we're distracting ourselves until we die. Pessimistic and correct, we wait for death and die.
Pessimistic and incorrect, we watch the future run away from us while we argue over what remains on the planet to be used by the technology we stagnated in. I don't want to know what 2050 looks like if we're still dependent on oil.
The worst case only exists if we're pessimistic as a species. The best case only exists if we're optimistic.
Though there are probably a multitude of ways of doing it, the two that stick out as most likely / agreeable to all are Gattaca and AI + Cyborg. Though I could also see strong AI either just replacing humanity[0] or simulating / uploading the minds of the good humans and merging with them.
[0] I'm not convinced that this would be a bad thing, a hypothetical AI that comes with all of the benefits of humanity with none of the rape or war might just be better ethically in a global sense.
It's stereotypical generalising of entire segments of the population into a straw-man caricature he can rage and rant against.
Honestly, I believe anyone who still thinks in traditional terms of left/right politically, isn't adding anything worthwhile to the discussion.