Due to population differences between some of the highest and lowest populated PvP realms, the following Free Character Migration will be available January 23rd to 29th:
From: Drak’thul, Kazzak, Stormreaver, Sylvanas, Twilight’s Hammer
To: Daggerspine, Dragonmaw
Please note that the migration may be closed at any time should a destination realm’s population rise too high. Please see the migration info thread for updates.
Original post by World of Warcraft Community Site