Beginning in just a few days, players who participate in the Recruit-A-Friend program will receive a whole new reward for showing a friend the ropes in Azeroth: the X-53 Touring Rocket, a two-seater flying mount that automatically increases its speed as your mount skill improves (up to 310% speed if you already have a 310% mount). The X-53 will be replacing the current Zhevra mount reward, which is retiring from the Recruit-A-Friend business after a good run. If you've already claimed a Zhevra (or claim one prior to the change), you’ll be able to hang on to it, of course. We’ll have more details on the new Recruit-A-Friend mount once it becomes available.
Current Recruit-A-Friend FAQ - http://eu.blizzard.com/support/article.xml?locale=en_GB&articleId=30562