I'd like to have there be a block placed above the main content area, which when the user has the right permission, allows him to set the 'section' of the current page (theme, or theme configuration set.. that i mentioned previously).
There would then be a checkbox saying 'cascade', that allowed you to cascade the setting all the way down with paths.
I think this needs to live in the menu system, which possibly needs to be refactored so that we can apply arbitrary attributes to paths (ie: not just the ones in the db table) Perhaps a data field would be enough for this ?
Interesting idea. Couldn't you do the cascade with a simple wildcard? If you wanted to cascade all admin/node pages, you just write admin/node* in a sections table. No change needed to menu.module