Well...I believe a possible epidemic could appear,or something... probably starting in a less developed country or a supervirus exposed to the world. And it moves around the world to fast to make a cure/vaccine.
OR a possible zombie outbreak. Well, now that they found that zombie gene in gypsy moths, i believe its highly possible that someone stupid will modify the gene saying 'oh we made a zombie gene for the whole human population' and thus zombie apocalypse...
or the divide between the rich and the poor gets worse and we all fight in a very long civil war (rich vs poor)/ the collapse of counties.
or we all get censored by more SOPA/ACTA/PIPAs and are controlled by a one world government of doom and destruction. We live life blissfully unaware of everything that is going on as people die around us...or something like 1984/Fahrenheit 451