Hi all,
as you may know, MediaWiki supports video embedding (from sites such as YouTube, for example) only via separately installable extensions. Many of these extensions are parser hooks (such as <youtube>), and as such they are a bit difficult to use for the average editor and many video embedding extensions are also very hacky and may even contain cross-site scripting (XSS) vulnerabilities.
What's the solution? A video extension that supports multiple different providers, is easy to use and is secure. So far none of the existing extensions really match all the given criteria. Until now, that is. Earlier today I committed the Video extension ( http://www.mediawiki.org/wiki/Extension:Video) into the official MediaWiki Subversion repository at http://svn.wikimedia.org/. The Video extension was originally written by David Pean, who is best known for his work on the social tools (http://www.mediawiki.org/wiki/Social_tools), back in 2007 for ArmchairGM (http://en.wikipedia.org/wiki/Wikia#ArmchairGM) and it saw limited use outside ArmchairGM, but the code was never finished. For example, while you could add videos to the wiki, there was no way to delete a video, which would've been a rather easy way for a vandal to troll the wiki.
During the past summer, I improved various social extensions (see http://www.mediawiki.org/wiki/Social_tools/Phase_II), including Video. I added support for deleting (and partially for undeleting) videos and I wrote plenty of new provider classes. While the Video extension is in pretty good shape now, it's not yet ready and it needs *your* help! Like I wrote earlier, the deletion of videos is possible, but undeletion support is not as functional, due to the way how Special:Undelete does things. [[Video:Foo]] links can't yet be tracked via Special:WhatLinksHere. And, of course, I'm not sure if Video supports your favorite provider yet. :-)
If you are a developer who's interested in video support or you know a developer who'd be interested in helping out, please see http://www.mediawiki.org/wiki/Extension:Video and http://www.mediawiki.org/wiki/Commit_access (if you don't yet have SVN write access).
Thanks and regards, -- Jack Phoenix MediaWiki developer