I'm reminded of an related set of proposals
I heard back in 2006 at a KDE conference.
Tim Eves, at SIL International, gave
a presentation on the need to add "font feature" and "alternative
glyph" support to ODF, in order to better support minority languages.
You can see his presentation here: http://conference2006.kde.org/codingmarathon/opendocumentday.php
I hesitate to go too far down the "desktop
publishing" route, but if there is a good case for supporting these
OpenType features, then I think we should consider it.
-Rob