Found here is mediawiki-mode, a major-mode for editing mediawiki-pages. This is a great major-mode to have if you use Conkeror as your web browser, thus probably finding yourself editing wiki-pages in Emacs.
Notes
Be aware that mediawiki-mode overrides the default save function in Emacs (why I’m not sure, since I’ve only used it for editing pages through Conkeror. Thus to be able to use it for editing pages in Conkeror you must find and delete the following line from the code:
(define-key mediawiki-mode-map "\C-x\C-s" 'mediawiki-save)
(this is a second line)
If you want to use mediawiki-mode with it’s original save function in addition to through Conkeror, you should rather change the keybinding to something else.