Please discuss: GTK/GNOME theme ideas

Hi.

I would like to say first to all involved, that GTK2/GNOME2 is fast and
beautiful (aa-fonts and tigert-crack); I compiled it last week and I'm
never going back to anything else.  Thank you very much for all of the
hard work that has gone into producing it.

I have recently come to appreciate the criticisms of GTK/GNOME themes,
especially when compared to their KDE counterparts.  Specifically, that
they aren't very user-configurable for the "average" user.  I noticed,
however, that in the GNOME2 desktop, fonts are no longer configured in
the GTK theme, but through the GNOME preferences section.  Thus, the
idea:

Why couldn't color, and even more generally, widget engine, etc., also
be set up through desktop preferences?  I know very little about
creating GTK themes, but I know that as long as I have the Thinice and
Redmond engines installed, I can use the PrettyOkayish theme, which
selects a different color and uses widgets from each engine.

I'm imagining an almost Windows-style dialog, where, for each widget, I
could select the engine used to render it, the color, and the font (if
applicable).  Granted, customizing every widget color would be ugly
(maybe simply base widget color and text highlight color would be fine),
but you get the idea.

There would still be downloadable engines (widget-rendering sets), which
require "advanced" knowledge to create, and themes (someone's idea of a
nice mix of colored engine parts), but it would seem to become trivial
to create my own mix or customize someone else's and save it as a new
theme.  Additionally, making a distinction between an engine and a theme
sort of clears up how things really seem to work.

I realize that pixmap themes may not fit well into this framework, but
they're sort of a different breed anyhow.

If this has been discussed already, I apologize, I did scan the recent
mail.gnome.org archives.  Additionally, it wasn't clear that a single
list would be the right place for this, so I sent it to a few of them. 
Thanks for your time and effort.

scott norris