It is my opinion that if that is where the WB skins must be then so be it.
BUT then put ALL of the other Stardock program skins there too! OD, CXP, DX, FX, etc., everything should be in the same structure eg C:\Documents and Settings\AllUsers\Documents\Stardock\ThemeManager,
C:\Documents and Settings\All Users\Documents\Stardock\WindowBlinds, instead of C:\Program Files\Stardock\CursorXP\Themes, C:\Program Files\Stardock\DesktopGadgets\AquariumDesktop2007, C:\Program Files\Stardock\ObjectDock\Backgrounds\OxidizedDocks3, D:\MyDocuments\Stardock\SoundPackager, D:\My Documents\ObjectDock Library\Backgrounds\Knot Vista, etc. to make backup of the files as painless as possible.
My Documents folder is on a seperate HDD and I back it up to a 3rd HDD. If everything (skins, etc.) goes into the structure on C:\Documents and Settings\All Users\Documents\Stardock\*, I can copy the folder to D:\ and have it auto back up to another HDD.
Count this as a vote for one (1) location for all.