I didn't
follow the whole discussion, but I just want to toss out one
not-so-stupid-as-it-may-seem possibility: HTML + CSS + JS. Take a look
at YUI.
I don't think it's stupid at all. Saying using browser technology for UI
is stupid these days is the height of short-sightedness. That's clearly
where everything is headed.
I have a working plugin (called "dirg") that provides a UI by hosting a
web server which you access in the browser. It provides a grid UI either
via a Novation Launchpad, or in the browser if you don't have a
Launchpad. Web UIs definitely have a ton of wins (think tablets, remote
control (i.e. network transparency), etc.)