It would be nice if there was the ability to enable banners that would automatically or manually show at the top of pages that need to be updated, need more info, etc. with a customizable message.

For the "needs to be updated" banner, a time could be set in the administration area (e.g. post banner if not updated for x number of months, years, etc.), while the "needs more info" banner could just be a checkbox when editing the page.

A good example of this is Wikipedia's "This section needs to be updated" banner (see screenshot).