One of the divisions at the company I work for produces computer based training. Much of the content is still sold on DVD even though it's also available on-line. Going forward we have no guarantee that a W8 PC equipped with a DVD will be able to playback the content on our DVDs. Furthermore we now have to support the vast array of crapware DVD players out there rather than having a standard (WMP).
If your DVDs conform to the standard they should play on all DVD players/software, right?
Which may be technically illegal since it uses decss (although, according to wiki, the one case that came to trial over decss resulted in an aquital)...
But yes, I don't see how this will help anyone. Users will just use VLC/decss and not pay the license fee, so the DVD industry loses money; MS's OS will be crippled and open the door to Apple ads about PCs not playing DVDs and general ridicule and the consumer has to go to extra effort to play their discs.