Hmmm, had an interesting conversation with aaronlev the other day about Mozilla accessibility:
http://sourceforge.net/projects/access-mozilla/
Should be working with him on some speech stuff soon.
Patrick Beard (of Netscape) and I are working on something called theme: for Mozilla.
Basically its a way of implementing skins for Mozilla on Mac OS (though potentially on any platform) which ask the operatng system to render the appearance of the controls (instead of using CSS or GIF/PNG images) thus ensuring the proper appearance.
e.g.
theme:button?pressed=true
will return a PNG of a pressed button in the current Mac Appearance theme.
You can check out progress in the Mozilla CVS at:
mozilla/netwerk/protol/theme