These moves are currently open and will go until Tuesday, February 10th at 8:00 p.m. PST or until they've reached their internal quota, whichever comes first. You can initate the character transfers by going to your account management page on worldofwarcraft.com.
Please be sure to move early if you want to. With the high latency and login queues on the realms we've seen many of these free transfer offers shut down early lately. Take advantage of this soon and be sure to bring over all your characters.
The full list of servers is after the break.