#0 - March 27, 2007, 12:52 p.m.
http://www.worldofwarcraft.com/legal/eula.html
B. You may permanently transfer all of your rights and obligations under the License Agreement to another by physically transferring the original media (e.g., the CD-ROM or DVD you purchased), all original packaging, and all Manuals or other documentation distributed with the Game; provided, however, that you permanently delete all copies and installations of the Game in your possession or control, and that the recipient agrees to the terms of this License Agreement. The transferor (i.e., you), and not Blizzard, agrees to be solely responsible for any taxes, fees, charges, duties, withholdings, assessments, and the like, together with any interest, penalties, and additions imposed in connection with such transfer.
http://www.wow-europe.com/en/legal/eula.html
B. In order to play World of Warcraft, you are required to establish a user account (the "Account") as described in the Terms of Use that is unique to you and non-transferable. To establish the Account, you will be asked to provide Blizzard Entertainment with an Authentication Key of the Game that is exclusively linked to the Account you have established with the Authentication Key. Therefore, Bllizzard Entertainment does not allow you to transfer ownership of the Game Client to third parties.