At the moment, when you render sketchup scene, corona render it with a default diffuse materials
using assigned color and texture native of sketchup.
I am just thinking that, we can build material editor from here.
Corona will detect native sketchup materials applied then auto-convert these materials
into corona own material, 1) diffuse material, 2) glass material, 3) glossy material etc etc...
Then corona will generate converted materials and open in corona material editor so we tweak
some properties to our liking then render.
I am thinking also of a drag and drop approach to material using preset but during dropping preset material will be applied but keeping the existing texture applied and not re doing or setting up again the whole process of texture mapping and lingking.