Microsoft's upcoming Metro format is being seen as a competitor to Adobe's PDF format. According to this article, though, MS is supposedly going to concentrate on creating a new "save as" function that will produce a document that is readable on any machine that has the reader software, as well as cleaning up the way Windows sends data to the printer. All the other heavy lifting that Acrobat does is supposedly not going to be challenged by Metro.
Although MS is saying that that they are going to concentrate on those two items and Adobe is saying that they aren't worried, I'm skeptical. Any time MS bolts on some new feature to Windows that takes over the functions of 3rd party software it doesn't bode well for the 3rd party. For users who want to create portable documents that anybody can read, if the stuff is built in to the operating system why are you going to bother purchasing a two hundred dollar piece of software to do it instead?