I would be very interested in this feature as well. I am currently trying to get the images from
http://www.silverstoneit.com/temp/mojo integrated into my current x-cart which has been modified heavily by the x-cart staff.
And to have a system that would easily allow for the swap of a whole extremely customized skin would be terrific.
Paul Stephenson
ps. I might be contacting you soon for some possible skin integrations as I am curious how much it would cost to have you create a custom skin and integrate it.