I would think, in addition to the lack of standards, privacy concerns would pose a huge obstacle. Case in point: It would be great if all of my doctors had access to a single, complete record of my medical history instead of my records being fractured among several healthcare facilities. The benefits are easy to imagine. Early diagnoses, personalized preventive care, etc., but then there would be a glut of personal information stored in a single array that could potentially be used by insurance companies to discriminate against me, or worse. I hope one day soon to see this healthcare evolution, but I also hope we can satisfactorily resolve these concerns.