This Saturday, November 12, Wikimedia DC is hosting an accessibility hackathon 10am to 5:30pm. RSVP at http://accessibilityhackathon.eventbrite.com/ .
If MediaWiki developers come, they can work on making MediaWiki more accessible -- https://bugzilla.wikimedia.org/buglist.cgi?keywords=accessibility has 129 bugs right now, so there's a lot of work to be done! Katie Filbert (aude), who's running the event, is aiming to get accessibility experts to the event to help developers improve their apps' accessibility. She writes that "at some point, we might do an "audit" of MediaWiki and identify issues ... maybe on Saturday."
Enjoy!