I'm thoroughly convinced that the real breakthroughs in medicine are going to come after 2 sweeping, society level changes.

First, everyone who is alive (or at least over 90% of the population) will have high quality, regularly scheduled medical attention. Basically a yearly checkup for everybody, take basic vitals, in addition to some blood, and a few other samples. These massive, population-based samples get screened for everything. Take every number and fact that can be squeezed out of those samples, and combine it with their personal history (Socioeconomic status, family status, intelligence by some measure, level of education, level of parents education, list goes on), to create a biological model of the entire human population.

Second, which we're working on now, is the development of data-analysis techniques that will be able to crunch these massive numbers, and find the patterns between genetics, geography, socioeconomic status, incidence of different kinds of cancer, etc.

As an example of my point, I tried to think of an important, easy to sample, and controversial metric in modern medicine. And then, how the study of the associated biological processes would be aided by a population wide, and generations long set of data points. Testosterone came immediately to mind. It's discussed quite often, used as a buzzword to rationalize and 'modernize' arguments of all kinds, even (maybe especially) arguments that have nothing to do with medicine. So, imagine for a moment that you had a comprehensive set of data, that contained the testosterone levels, basic vital data and personal histories of the entirety of the human population, from 1800-Present. You could model this on a globe, looking for 'hotspots' of relatively higher testosterone, and compare them to other 'hotspots' and look for similarities in diet, disease, lifespan. You could look for deep valleys in that model and compare the same, who knows what you'd find? Or what a Watson-descended computer with the sum of all of humanities medical knowledge at it's disposal would find?