I think since no Microsoft engineer actually owns the copyright to their code, they can't decide why license to put it under. And it's probably easier to put something on your standard MSFT EULA then under the Ms-PL.
But this I think is a perfect example of something that should be Ms-PL.
Unless MSFT really doesn't want open source projects to showcase some of the cool features of Windows 7, and inadvertly build dependencies on their platform. But that's just retarded.
There is some clauses in the license that is worrying to properitary developers too.
"[you must] indemnify, defend, and hold harmless Microsoft from any claims,
including attorneys’ fees, related to the distribution or use of your
programs or to your modifications to the software."
So if one of my customers sue Microsoft, I have to foot the bill for the lawsuit? Screw that.
I don't think it's safe for anyone to use this library at all. It's a legal liability.
Change the license.