Normally there are only a handful of servers involved when Blizzard opens the door for free character moves. However Bornakk announced today a total of 22 U.S. servers that you can move off of. There are various groups of servers, labeled "Source A" through "Source E", that are allowing free moves to destination servers, labeled "Destination A" through "Destination E."
If you are interested in taking advantage of these free moves, get in quickly as these offers have been known to close down once Blizzard meets their transfer goals. The transfers begin tomorrow at 12:00 p.m. PDT and end at 12:00 p.m. PDT on November 4th (election day, next Tuesday). You can begin the transfer process by visiting https://www.worldofwarcraft.com/account/character-move.html when the transfers are available starting tomorrow.
The full list of servers are reproduced for you after the break.
Good luck if you're moving!