Love that you guys are addressing more than just the security rule - we found the technical parts of HIPAA the simplest to address. Are you planning on having employee training modules and customizable policies and procedures? How do you help guide companies through the Privacy components?
One interesting feature to add at some point would be helping companies incorporate their BAA into their user agreement (this is how Practice Fusion does it - http://www.practicefusion.com/pages/user-agreement.html).