Was searching to confirm about mounts and stumbled across a blog. Nothing about mounts in it but it has some leakage.. mostly negative
Age of Conan: AoC Beta Questions: Zones, Traveling and Mounts
This actually seems to imply it is pre-order only but states they aren't nearly as beneficial as horses, being slow and only having animal attacks instead of player attacks:
Age of Conan Hands-on for PC - VideoGamer.com