Registering at any site related to Dofus, Dofus Arena, or Wakfu will give you an account for Ankama Games, which allows you access to any of their games and servers. If I'm not mistaken, this also means that subscribing your account for a month would pay for all of their games since the account is universal.
As of now, we are playing on the French OB server. The English CB is limited and the keys have already been given out. The only way anyone here would have one is if they were tracking Wakfu before we even announced it at MMOGames.
I'm not sure if they are translating the client for the French OB into English or not, but it does say that Tiva is a French-speaking server. This is how they had it in Dofus... an English client but servers for international users. This is just speculation though. We'll see what turns up when the English server goes OB.