Over the last week Microsoft has put out specific promises on privacy and interoperability for the community to review. (The picture is from the blog of Microsoft evangelist Viral Tarpara. I can't tell if the TV show Scrubs has endorsed the product. Hopefully their lawyers can.)
These are all substantive moves which can be tested, critiqued, and implemented by other vendors.
Google, meanwhile, has basically gone beta. The Cleveland Clinic will link to Google Health and try to interoperate with it. The pilot project is drawing more media attention than any of Microsoft's moves in this area have so far.
One can argue that this is just how the two companies roll. Microsoft masters each step of the process methodically before delivering a product to market. Google throws something on a Web site and, like Tom Sawyer, lets its friends whitewash the fence.
In the context of the medical market, however, Microsoft's process seems more reasonable. This is less about gaining the trust of consumers than it is about winning over doctors, hospitals, and payment processors.
So far, advantage Microsoft.