Where to Draw the Line: Book Illustrations, It's Not Just for Kids

While childrens' stories are beautifully illustrated, it seems that book illustrations have gone out of fashion for adult fiction. It would be nice to bring them back again.
In the past they were used, in part, for the benefit of any illiterate readers, which there were more of at the time. My favorites are the illustrations for Jane Austen's novels by Hugh Thomson and C.E. Brock. They really captured the essence of her characters.
I will be illustrating my upcoming novel series, Mr. Austen and later Kate Hawkins.
I think book illustrations contribute a certain feel to a story.
So, let's bring back illustrations to adult fiction and don't let the kids have all the fun!