The current version of Minefield (the pre-3.1 nightlies) has Ogg Vorbis and Ogg Theora support.
You can try these out using Wikimedia Commons video:
http://commons.wikimedia.org/wiki/Category:Video
The current MediaWiki video code defaults to everything else first,
but load the video then select "More ..." and you should see the
option to try it out, report bugs, etc.
Is the <video> tag doing Ogg Theora in Opera yet?
I'm sure Apple and Nokia can join the party at their leisure.
- d.
