Blizzard is opening up some additional realm transfers starting tomorrow. If you are on one of these high population servers you may want to consider switching to a lower population one.

New Realm and Character Transfer - Eyonix on 1/30/06
On Wednesday, February 1 at 3:00 AM PST, we will be opening a new PvE realm: Eitrigg. Players with characters on the realms listed below will be able to transfer their characters to this new realm. The transfers will be available until 3:00 PM PST, Wednesday February 8. During this time, standard character creation will not be possible.
Argent Dawn
Bloodhoof
Khadgar
Zul'jin

Character transfers are available Monday thru Friday from 3:00 AM to 3:00 PM PST. If you're interested in transferring your characters from the realms listed above to the new PvE realm, please click here.