Ben Riga has just posted information regarding the WPF Healthcare prototype source code have been released. This is an old demo (PDC 05) but still one of the best I have seem (maybe due to lack of public prototypes).
Within the zip file you will find the source code, some gadget source code and documents breaking code the application and code which is cool!
Download it from the link below and have a look at this great application, maybe get some ideas for your next application. Looking forward to getting some time for WPF soon (well, one can hope).
Links:
http://blogs.msdn.com/benriga/archive/2006/11/02/wpf-healthcare-sample-source-posted.aspx
http://wpf.netfx3.com/files/folders/applications/entry6608.aspx