Because they will close the transfers early if necessary, Drysc highly recommends that if you are planning to move your characters that you do so as soon as possible. If you wish to take advantage of the free move, go to this link, where it will ask you for your account info before proceeding.
Blizzard has also opened a new PvE realm, specifically for this transfer. New character creation on Caelestrasz will be turned off until the transfers have been completed.
The eligible Oceanic realms are listed after the jump.