There has been some information released about Mounts in Warhammer: Age of Reckoning.  There have even been sightings of horses and even the gyrocopter gizmos used by the dwarves if you watched the ORDER PVP VIDEO closely.  For now though, EA has given us the following basic Mount information.

Mounts

Are you tired of running everywhere you go? Take a load off those aching feet and get to where you want to go faster with your personal mount. Ride a ferocious wolf with your Goblin, a powerful warhorse with your Priest of the Empire, or a personal Gyrocopter with your Dwarf. In fact, each race gets its own special mount, with a few surprises thrown into the mix.

• Can purchase Mounts at the City Stables at rank 20.
• Gain a significant speed increase.
• Cannot use in buildings, caves, or other interiors.
• Cannot use in deep water, or in some areas and zones.
• Look at all of the pretty saddles everyone is mounted on – Even most of the NPC’s!
• Use the mount item (right click on the item in your backpack or left click from hot bar) to summon the mount.
• Cannot use any abilities or enter into combat while mounted.
• You will be dismounted most of the time when you are attacked.