Note: these are just a few of the case studies for WPF in Line Of Business; to see more ( or a longer list ) please check our case studies site and do a search for "Windows Presentation Foundation" or similar.   
Also, this list focuses on "line of business" if you want consumer applications, you can find loads of WPF apps at the App portfolio wiki on channel9.  

 

From Microsoft:

 

History:

Rev Updated Comments
1.0 12/15/2007 Created initial list..  Not all inclusive. Drop me a line if your app needs to be added