I did this exact thing! almost. It builds a single XML
file out of a directory tree that contains the glade
xml and perl scripts then using the perl module
Snapper the application os run out of the file. It
only works under Gtk-Perl not Gtk2. I was working on
it quite a bit a year or two ago but I couldn't drum
up much interest and I have sinced moved on to a new
project. I thought it was really cool, it even had an
IDE and app launcher that was a single XML file. It
could pull the application from a URL or __DATA__
section, etc.
If you are interested it is located at:
http://sourceforge.net/projects/snapper