Hi Shawn,
I'm currently working on the Memento Extension for Mediawiki, as announced
earlier today by Herbert Van de Sompel.
This is very exciting! Coincidentally, at last week's SMWCon (the Semantic MediaWiki conference) in Berlin I gave a presentation to argue that we need some sort of 'time travelling' feature (slides are available at http://slidesha.re/1iIf3F9). One of the other participants also pointed out the Memento protocol.
Are you familiar with Semantic MediaWiki (http://www.semantic-mediawiki.org/) as an extension to MediaWiki? I'm curious what it would take to let SMW play nice together with Memento.
Kind regards,
Remco de Boer