I finally have a cool screenshot to show you of our new real-time global illumination working.
Here is a comparison screenshot showing direct lighting only:
Now there are still lots of small issues to worry about. Right now I am only using a single cone trace. More cones will improve accuracy, but I think light leaking is just always going to be a fact of life with this technique. Still, the results looks great, require no precalculation, respond to environment changes, and don't require any setup. Win!