WMP is no longer developped for Mac OS X. Instead, Microsoft has licensed Flip4Mac, a Quicktime plugin, for playing Windows Media files. Like WMP 9, it plays WM files just fine, unless they're DRM'd. Usually, if neither Flip4Mac nor VLC can play a file, you won't play it without running Windows.
Mac user since 1987. Running Mac OS X 10.8 Mountain Lion on a MacBook Air 11" & an iMac 27" and whatever's newest for my iPhone 4s, iPad 3 and AppleTV 2.
Apple Certified System Administrator 10.6, Apple Sales Professional 2008-2011, Apple Certified Mac Technician.