WOW - Forced Name Changes for Some Players : World of Warcraft General Discussions

Rather then deal with them on a case-by-case basis via GM intervention, Blizzard has decided to handle the oddball names with funky characters in them via software. Thundgot had the following to say on the subject:

We wanted to inform players whose character names contain letters from the Cyrillic alphabet that they will receive an automatic forced name change upon the release of patch 2.2.2. Allowing the input of Cyrillic characters in names was the result of an accidental code change. We apologise for any inconvenience that this may cause. Cyrillic characters will still be usable in the in-game chat, however.

Patch 2.2.2 is hitting the European servers as we speak. It is unclear at this time if the forced name changes will only be enforced in Europe or if the policy will eventually bleed over onto the North American servers.