The bottom line is, both Google Health and HealthVault are eager to share my information with third parties without giving me enough control over exactly how much and in what manner. This aspect is absolutely a Priority Zero [that is, higher than Priority One :)] for personal health record (PHR) software.
MSDN blogger Tatiana Racheva gives a gut-check review of both Microsoft HealthVault and Google.
Amazing read, and she brings up points several docs and ePatients have been sharing on Twitter for months.
Give yourself 20 minutes for this one - reading + synthesis + assimilation.