The problem with trying to make an 'open document standard' is that everyone thinks they have an 'open document standard', so you end up with 30 'open document standards' that confuse the less technically inclined users and infuriate the more inclined.

Personally, until a better (read: equally universal) format comes out, I've got my document library saved as both .txt (unformatted + UTF-8 encoded) and .doc (formatted). Everyone uses both, at least.