Internationalized? Surely they mean localized!?
Even been traveling? Notice how keyboards in most countries are different, localized for accented characters and such? Until now, you could always find the ASCII letter you were looking for but this takes it to a whole new level!
Imagine you are Russian and you travel to England and go into EasyInternet to check your email. Uh-oh - you only know how to get to your ISP's webmail using the Russian IDN.
Sure, most website will end up supporting both, but because you didn't think to find out what the ASCII URL was before you left, you are screwed.
Not to mention I might think of doing business with some Russian company and they might have forgotten completely to provide for a domain name I can actually type in.
They call these "Internationalized Domain Names" while in reality they should be called "Localized Domain Names"; domain names that can only be accessed from one locality - the one with the keyboards that can input them.