I imagine. What if you can draw with shaders. Produce a 2D drawing with the tablet pen and have shader effects like in the node editor.
So the idea is to draw in 2D without the need to model a 3D object. Then let the software adapt the paint in some cool fashion.
Here I wonder if you could paint something like a reflection map, a depth field and combine these layers in a smart way.
Maybe its possible to draw with realtime rendering in openGL. Just because its possible.
So the target of the idea is to enhance paint tools with the functions of 3D software. I think this idea could produce some pretty impressive digital drawings.