As far as I'm aware there have been zero peer reviewed publications showing Watson actually doing something in medicine. When a doctor thinks he or she has a better approach than what is being done, they use the scientific method to find out of their hypothesis holds up. So far I've seen lots of IBM conference presentations and press conferences. But where is the data? Where are the increased survival rates? Where are the reduced medical errors compared to controls? That is science. Everything else is snake oil unless you have that.