I see a lot of potential for this, though not necessary with any error "Missing Language Key", as this hints to a missing default locale string.
But we could turn on Babelfish support seperately with each locale, so the language string would be translated on the fly. It remains debateable whether we should store that string in the OpenACS database though (the latter would boost performance, but then you have language keys in your installation that are not reviewed on the translation server).
In any case, we should at least enable the babblefish translation as the default string for new translations on the translation server (though most likely the experienced translators will moan at this idea).
