[frabjous]

I agree with Charleski. Choosing the fonts, even the body text fonts, most appropriate to a given work is a task that should be assigned to the publisher, and is part of the art of publishing. Indeed, I think the authors of the book should have input, feedback and even veto power into it, whenever possible. (Though responsible publishers should resist wild choices on the parts of authors.)

That said, rendering devices should have the ability to override that choice, particularly when it is necessary for people with vision problems, or the font chosen clashes with a particular display medium, but generally, the fonts chosen should be considered part of the book.