No big news, as with IE, Media Player on the Mac is redundant. Why sell software where it's not needed, and not really wanted either. Remember, QuickTime on the Mac isn't just a player, it's part of the core operating system.
The article says they will do a plug-in, so my guess is a wmv/wma plugin for Quicktime so that MS still has a media presence on the Mac, at least in their formats.