Microsoft recently released a new theme for Windows XP to promote the new Zune media player. Unfortunately the WPF team did not create a suite of control styles for this theme. As a result WPF controls running under the Zune theme are rendered using the Windows-9x era "classic" style. Fortunately controls under the Zune theme are quite similar to the "metallic" windows XP theme. Using reflection as shown in this sample application it is possible to fake out WPF to make them think they are running under a different theme.
[disclaimer] This code needs to run while the application is loading. It uses reflection and native inter-op, and thus is unsuited to XBAP applications or other lower-trust environments. Handling theme changes while the application is running is left as an exercise for the reader.