Blizzard has mentioned that they have made free realm transfers available for selected realms!

With the launch of Wrath of the Lich King, we’re seeing a very active and growing population for many realms. As we continue to see players actively participating in the new expansion, we’re keeping a watchful eye on any resulting queues from high realm populations, and will offer free realm transfers as necessary to help keep populations at an appropriate level. We've created a post in the forums that will contain all information on these transfers as we offer them

Check if you are applicable by clicking here!