We have some early results on The Great Microsoft WSDL's Hunt. I've looked around myself and they're not as easy to find as you might think. I'm still encouraging any and everyone (including Microsoft employees) to send me the WSDL's!!
I also published the names of a few Microsoft products that likely have WSDL's.
Come on Microsoft - we're on year 5. Surely you've got more than 4 WSDL's???