It started out as a master bedroom sized beast, and its first task was to beat two world champions at Jeopardy™. Once it had handily mastered that task, the fine folks at IBM scaled it down to the size of a pizza box (while increasing its processing speed by 240%) and taught it to assist in making medical decisions. I’ll let you read the full article from the Forbes here: http://www.forbes.com/sites/bruceupbin/2013/02/08/ibms-watson-gets-its-first-piece-of-business-in-healthcare/
The bottom line as I see it is there there is an amazing opportunity here to add a sanity check to health care decisions, reducing the cost of medical mistakes by billions of dollars, and also to extend health care knowledge to regions that are lacking skilled practitioners. As its abilities are fine-tuned, and costs go down, this could lead to a sea change in how health care is provided.