I'm not sure where to put this, so I suppose here is as good as anywhere. 

What are your thoughts on illustrated novels? Not necessarily an every-other-page deal, but fantasies with the occasional surprise image like in "Wicked" or "The Stand." Do they add anything to your experience? Help guide the way you imagine the settings, characters and events? Or do they interfere in some way?

I love surprise pictures. I like the marrying of the verbal and visual interpretation of events.

Where in the querying/publishing process does supplementary illustration get discussed? Is it the author who requests or submits it? Does it fall to the agent/publisher to recommend such a thing?