As most of you know, Korean gamers kept their Beta characters and took them into the final release of the game, which is probably the main factor behind the slaying of Onyxia so soon after Korean release. Blizzard wanted to clarify the reason why they didn't wipe characters by pointing out that Korean gamers did not recieve the 1 month free trial like the North American boxed versions and also that the fee is higher, around $24 a month. Players can download the game for free but they do have to pay the higher price each month.

Based on the facts that EU gamers will have boxed versions and will also pay a lower monthly fee, we can assume that EU beta characters will be wiped :)