It would be cool to able to set the visibility of some layers ON / OFF only in the viewport. For example, I am working on the interior of a building, so I don't want to see the whole environment during modeling, becauses the huge distances mess up my viewport. But when I run a testrender, I would like the environment layer to be turned on, without having to deal with turnin On/Off layers every time.
So it would be nice if the layers could be set to On / Off / Off in Viewport / Off in Renderer just like for modifiers.
Of course "Off in Renderer" is already a function if I turn off Renderable in its properties, but it does not work the other way around.