Rob Church wrote:
It would, I think, be very possible to write some sort of tool which can quickly extract this information from page text, and then present some sort of editor - saving it would require replacing the information back into the page text, and saving this again, which would conveniently handle the update, plus logging and versioning in one go.
Rob Church
There's http://commons.wikimedia.org/wiki/MediaWiki:HotCat.js for categories.