We already have internationalized email addresses, in a sense, you can
put a multi-lingual phrase before the address. A few email clients (that
I hate, but whatever) actually don't even show you the email address,
they just show you the (multilingual) name. So, its possible to write
your name in any character set you like beside your address.
The idea of multi-lingual local-parts sounds great, the inability to
communicate with people in other countries doesn't. I couldn't even
get a chinese speaking friend to type in a chinese email address on my
machine, since I don't have a chinese character input method for Mutt,
so even literacy wouldn't necessarily help!
Somebody else mentioned the hotel in Turkey with the Turkish email
address. With a phone, I may not be able to speak to that hotel keeper
in Turkey, but I can dial his number with my phone, and my roommate
speaks French, and maybe so does he a little, so she can help me out.
Email needs to be like that.
Cheers,
Sam