no.. there isn't any skin freely available to download.. like vB.org.. It is designed specifically for this site by its developers.
as panda said.. princeton has released a few mods that are used here on the site like
quick reply to pm sender,
pm preview,
usercp navbar interface.
You'll even get a mod. that displays the table in the footer with the
New to Site and
Need Help? columns and also the mod. for
Sitemap like vb.org