I think the site's main content area could be just 26 pixels wider. Why?
Simply because that way, scenes would not have to be scrollable :) Scenes are a big part of the site, and I think it would only be fair they were used as a template for content area size.
The current width of the GUI is 910px, but if it were extended to just 936px, this would be the result:
I only don't know if this would affect mobile players in any way, since they are already dealing with small screens, but a 26 pixel increase hopefully won't make navigation much harder!