I've created a skin based on Windows Media Player 12 (the latest version, included in Windows 7). It's good for those who want a simple, clean skin with minimal interface (i.e. not taking up half of the screen) and, especially, those who are very comfortable with WMP's controls. I also felt it important to include as many of the skinnable controls as possible (moreso than existing skins), so all sizes have "Open", "Playlist", "Mute", "Previous" and "Next buttons and most have "Shuffle", "Repeat" and "FastFwd" buttons. I also added text labels to the buttons because it takes the guesswork out and makes the skin more comfortable to use, IMO. If you'd prefer no text labels, open the Background.bmp in a paint program and paint over the labels with black.
The following sizes are included:
For Windows Mobile phones...
For CE Core (PND/GPS) devices...
If you need a different size, see the included Readme for some simple instructions on how you can modify one of the existing sizes to whatever size that you need.
Note: I didn't test every single size, so there may be bugs. Feel free to point them out to me (or, even better, correct them in skin.xml, yourself, and tell me what the corrections were).
EDIT: Replaced all tabs in the XML files with spaces to satisfy a bug in later builds of interface.plg.
EDIT #2: Added HVGA (320x480) version (for the HTC HD Mini, for example).
EDIT #3: Added the same grey background to the 240x320, 240x400 and 272x480 versions that the larger sizes have.
EDIT #4: Magnified the size of the controls for the 480x800, 800x480, 480x640 and 640x480 skins. (Note: all releases until this point have been downloaded a total of ~1400 times)
Download from MediaFire: TCPMP WMP12 Skin.zip
Download from xda-developers: (see attachment)