Once you begin the World transfer process, you cannot create new characters or log into the game until the transfer is complete. A large number of players are expected to make use of the World Transfer Service during this free period. As a result, transfers may require several days before processing is complete.
Even those who get to do this are getting screwed really. We lose up to maybe a week of game time that we paid for? I mean yea I could log in, screw up my account, and then take a month to try to fix that problem, woo. They should have done this during the free trial/extended period, not forbid it from those still on it.

Oh, and the real kicker in their disclaimer

Please note that the Square Enix Support Center cannot assist with certain problems if more than one week has passed since using this service.
I can see this going real well.