Microsoft has released a download that allows you to play Windows Media files (.wma and .wmv) directly in QuickTime – on a Mac. Hey it is a Microsoft technology we are talking about here :-)
With Windows Media® for QuickTime, by Flip4Mac™, you can play Windows Media files (.wma and .wmv) directly in QuickTime Player and view Windows Media content on the Internet using a Web browser.
Optimized for High-Definition Playback
Windows Media® Components for QuickTime has been highly optimized for Power Mac G4 and G5 and Intel computers and supports playback of high-definition Windows Media video files.