there was a topic recently that said players wouldnt be able to transfer servers until sometime after release. so for example if you logged out on sargatanas thats where you'll log in on the release of ARR. (subject to server names) but the regional servers weren't going to be opened to existing players immediately or something along those lines.

the idea was to give existing players a chance to decide with friends and linkshells etc where to go or something rather than just log into arr and find all your friends are somewhere else.