I manage a website (using WP as CMS, not blog) with a lot of pages (41 and counting). It takes a several seconds every time I have to switch between pages to edit. I think a nice feature would be to have a dropmenu of all the pages next to the "New Page, Draft, Upload..." dropmenu at the top of the admin. This would save a lot of time jumping between pages you have to edit.
I suppose a plug-in would be an easy solution for this vs. a new WP feature, but I'm not equipped to create this myself.