I really can't wait until the phishers get their hands on this. It's going to be a gas.
That way the characters are respected, but the user is alerted if a very similar (non-ASCII) code has been used to dupe a user.
EDIT: As I understand it, Cyrillic languages use code page 866 as an extension to ASCII http://en.wikipedia.org/wiki/Code_page_866. Is this correct?
To the best of my knowledge, Cyrillic languages don't use the Roman script (except where letters appear to be similar). The ASCII subset of codepage 866 is for "cd C:\", not for Cyrillic.
All of them define the whole alphabete, though, so even the letters that look similar to some latin letters are always encoded differently.
http://xn--55gaaaaaa281gfaqg86dja792anqa.ws/
This is to prevent phishing. Hardly ideal, but it works.