> I'm kind of getting an idea of where this will go
> in the UI, probably there will be some stuff in
> Options / View to control the default light setup,
> I should be digging into that pretty soon here.

As in a place to alter the light parameters (ala Rhino) or as a simple combobox to choose between "diffuse" and "metallic"? If you made the light parameters accessible via the javascript interface I can imagine someone creating a plugin where a dialog window pops up with preview icons allowing users to easily select different custom lighting schemes.