In response, Adobe went to EU regulators earlier this year to ask that they bar Microsoft from including XPS support in Windows Vista, fearing that the ability to create XPS documents "for free" could cut into their ability to sell PDF creation software to Windows users.
Aside from the fact that OpenDocument is available for free like aldo mentioned, what is stopping people from making PDF files for free?
OpenOffice can export files to PDF format, and it's free...

Also, for example my printer/scanner software can make PDF documents from any scan, but it's not actually free, it came with the printer-scanner, which came along with the computer when I bought it, so in a way I did pay for it.
Anyway, it's good to have some options to PDF files. I don't like them very much, and since they are quite common nevertheless, they are a bit of a PITA. We'll just see how they pull the file type off and how many security breaches they enable with it.

I know it sounds impossible to do that, but hey, we're talking about Microsoft here. The firm that can make image files be a security risk - WMF, anyone?
I'll wait and see how this file type turns out to be until I start cheering. What are the odds that it'll work without problems on other platforms than Windows Vista? Can it be used by Linux or Mac users? Remains to be seen, I suppose.