Health is a complicated subject: usually you care about it only when there's something wrong. Google's Adam Bosworth realized people aren't in control of their own health information. "There is no place individuals can go to get a comprehensive set of health and medical information about themselves. Access to this comprehensive information can be vital to proper and timely diagnosis of the patient, to the patient getting the best possible treatment, and, perhaps sometimes overlooked, to the patient getting the best possible ongoing care and support after the initial treatment, especially for chronic illnesses. (...)
We need to put control into the hands of the sick and their caregivers and to gently suggest that those who treat them, medicate them, test them, or diagnose them, are out of date if they do not instantly deliver this information to the patient. Once this happens, we will see truly great decision support systems and specialists and health coaches help the hapless patients much more rapidly determine what is truly wrong with them."
Your health record can be shared between healthcare providers if that's necessary, so an easy-to-access health URL that works like a private Google Docs document, to which you can invite people, is just an evolution.
This is one of the preconditions of a Google Health product, that manages health records and helps people use them better.