We've blogged earlier on rumors that Google might be developing a Google Health service and that Adam Bosworth might be involved as the "chief architect" of it. Now some confirmation from Google, which emailed me:
Health has been an area of interest at Google for some time. We (including Adam) have been doing a variety of research in this area, including how to improve the quality of health-related search results.
So, they're looking at it. What may emerge obviously remains to be seen.