World of Warcraft account required Battle.net 

WOW  is now a part of the new Battle.net! In preparation for the rollout of Battle.net£§s upcoming communication and community features, as of today, all WOW accounts must be merged with a free Battle.net account in order to log in to the game. To upgrade to a Battle.net account, please go here. For more info, check out the Battle.net site or read the FAQ.