Imagine a time in the future when a major disease like cancer is cured. I know it's a long way off, if at all, partially because some of these things are genetic and DNA is not easily reprogrammed.
Cancer is one of the major killers of mankind. Without it, and with more people living longer, population control will become a much greater issue than it is now. So how will we deal with that? More widespread (even government mandated) use of birth control? Child limits, a la China's one child policy? More wars? Rebirth during the fiery ritual of Carousel? Colonizing other planets? Involuntary euthanasia? Something we haven't thought of yet? Tell me your ideas.