User called marxo found a new Windows XP MCE-like theme in the latest CTP of Windows Embedded:
This style can be found in the Windows Embedded Standard CTP Refresh. It's called "Embedded" and, along with the wallpaper, gets copied into the image if the Windows XP UI component is added. As it's digitally signed it works with any XP/Server 2003 install. The archive I uploaded below contains the Embedded folder and the Embedded.theme to be copied to %systemroot%\resources\themes and the wallpaper in its original format and size.
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