I did find the official WPF docs and examples rather simplistic. Most of the advanced stuff I luckily stumbled upon on forums or blog posts. Perhaps developers don't have enough information to build upon the simple examples.
I believe most, if not all, of MSDN now supports user-contributed content alongside the API refs.
Thus, it would serve your fellow developers if you were to annotate the lacking documentation with (1) example code or (2) pointers to the blog postings that you found.
