Media Center is a 10 foot interface. The others are not.
Can Zune software sync with any mp3 device? If so, then kill off Media Player. Redirect any DLL calls to Zune.
As far as Windows 8 requests...
- .NET/WPF takes a more central role, moving more of the OS code to managed where possible
- Removing more compatibility code. There's no reason to continue support for Win 9x applications
- Required Internet connection with only basic drivers included on installation disc
- Central place to find, buy, install, and uninstall applications (similar to Ubuntu's software center).