If you still have a couple friends who are holding out on playing WoW, now is the time to put a bit more peer pressure on them. Once you recruit a friend that signs up for 2 months and puts you down as a reference, you will get a shiny new Zhevra mount.
The Zhevra mount actually isn't the only perk you'll be seeing either. You can actually summon the friends you recruit to you so you can level together. Another nice little bonus is that you and your friends will get triple the experience up until level 60.
Which means not only do you get a cool mount, you can get one of your lower level characters to level up much faster. The experience boost does have a little fine print to it, you can only get that boost in experience if you are both together. Also if one of you is lower level, only the lower level one will get the xp boost. You can read up more on the details here.