You know, I've got a few clients, and at least a few friends and acquaintances that never use a drop down. They just click on the top level in the nav bar and go from there. The reasons vary. One person I just can't seem to get to use them. Another has some slight motor skills issues with arm and hand movement and drop downs drive him totally mad. Still others, I just don't know.
I for one would like to see a selectable feature that would list the child pages at the bottom of the content area on pages. It is kind of a pain in the ass to have to scroll back up to the top of a page so that you can get at a drop down menu to see what else is available as a child under that particular selection. This is one of the reasons that when doing a standard website, I nearly always include navigation links at the bottom of the page - or at least the main links.