According to MS ..."WPF is largely written in managed code on the common language runtime, it never ran in kernel mode."
http://www.microsoft-watch.com/article2/0,1995,1902540,00.asp?kc=MWRSS02129TX1K0000535
http://www.techworld.com/opsys/news/index.cfm?newsid=5002&inkc=0