All of these 'technologies' may be exciting but they have some sinister problems as well as you have clearly state here.
I'm most fearful of....
all of them
Nuclear war is imminent.
Global Panademic: Pathogens are getting harder to get rid of as they grow into antibiotic resistance.
Nanotechnology: These small buggers getting inside our body which can wreck havoc.
AI: Horror of a robotic takeover