I suppose a skin made for 7 would work on Vista, provided you skinned the Vista Specific things; for example, the start panel log off buttons...they are different for Vista.  Personally, I only skin for OS's I have, which are Windows 7 and XP.  And that is a pain in the butt, because I wind up half the time having to make separate start panels, taskbars, tree nodes, systray arrows, start panel arrows, etc., for each OS.  I have Windows 7 on my desktop, and XP on my laptop.  I know there are some folks here who dual-boot...maybe one of them will chime in.

What you could do is have someone who has Vista to check your Windows 7 blind on their OS...and let you know if it works or not.

It will be very close to being Vista ready...maybe not perfect but damn close.

Truthfully skinning for Vista isnt a priority anymore unless your selling themes.

XP still has over 50% of the desktops and Win7 passed Vista last spring in usage.Vista never topped 20% and is declining.

Vista users dont hate me please...I still make the Vista sub...for now...buhwahahahahahh.