GTK theme plugins?

I’ve recently started investigating the gtk2 gem with Ruby 1.9.2 on
Windows using the RubyInstaller build recipes. It was a pleasant install
experience and I think it’s clever that you’ve bundled the dependencies
under vendor/local subdirs.

A big thanks to all of you involved with delivering this capability
and also making it available as a mingw binary gem!

With GTK+ apps (eg - Sylpheed) one can usually change the theme via
tweaks to etc/gtk-2.0/gtkrc, adding a DLL to lib/gtk-2.0/2.10.0/engines,
and adding a theme directory to share/themes.

From an earlier discussion with Kou, I understand there’s not currently
a way to set the theme from a Ruby script by doing something like
calling a method after require 'gtk2' but before Gtk.main. I also
understand there’s not currently a way to use optional “theme plugin
gems” (eg - gtk2-glossy) that you could then require and use from a
Ruby script.

I personally prefer the idea of theme plugin gems, but don’t yet have
enough GTK+ experience to know what the key technical hurdles are. For
example, is it even possible to logically meld the optional theme gem’s
theme engine DLL and share/themes info with the gtk2 gem’s vendor/local
structure by orchestrating things through the gtk2 gem’s
library? If not, what other options exist?

Is there any interest in finding a solution to setting GTK+ themes from