This is something that has been bugging me for a while. My game has heavy fog in it, which is fine through the game camera but means that when you zoom out in the Scene Editor everything is fogged in and you can't see anything. I've been turning the fog off in Edit->Render Settings and often I forget to turn it back on. Its an annoying workflow. Turns out you can toggle a variety of effects on and off for the scene editor and fog is one of these. Lighting is another, which will be useful for sinister night levels, I'm sure.