Apostolos,
I would recommend against following this dangerous path. Once I asked I asked the luaTeX list how to load hyphenation patterns and practically no one knew the answer! So I think your decision is wise.
Interesting, because my experience when developing babel is quite the opposite -- loading hyphenations patterns in luatex was trivial, much simpler than with other engines. Anyway, the average user shouldn't be concerned with those issues because a higher level interface is the way to go.
PS I think that we should not talk about luaTeX here.
Agreed. Cheers Javier -------------------------------------------------- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex
