Skinners have an excellent opportunity to update their skins to take advantage of Windows Vista with minimal work: Vista shadows.
WindowBlinds 5.51 supports painting the shadows in Windows Vista as part of a UIS2 formatted WindowBlinds skins.
To add support simply open the UIS file and in the [Personality] area add: AllowVistaShadows=1 and from then on, on Windows Vista, your skin will display the Vista shadow underneath it.
Feel free to update your WindowBlinds skin on WinCustomize to support this feature as Vista users will likely appreciate the cool results!