Well the experiment with Firefox skins (https://www.wincustomize.com/Skins.aspx?LibID=38) finally came to an end. 

We don't remove sections on WinCustomize.com but only the most popular sections remain highlighted. Last month, 0 new skins were submitted. In fact, it's been going on 2 months since there was a new Firefox skin put in.

This paves the way for Trillian and other galleries to get a shot.