The latest beta build introduced additional mounts and companion pets into the game. With a new patch pushed onto the beta servers, check out these videos of the guild faction mounts! The Alliance version above is called Reins of the Golden King (which is an awesome lion).
Interested in seeing what the Horde mount is? It is the Kron'Kar Annihilator (a scorpion), and you can see a video of it after the jump!