European community manager Ancilorn posted in the Cataclysm forums that there might be an alchemy mount in the future. There are extremely little details for us to speculate on as this could mean something from a flying broomstick to a potion you drink in order to become a mount yourself.
However, one thing that we can be sure of is that there is at least talk of doing this, but nothing is certain. We can probably also expect such perks to pop up in other places as all professions are getting a revamp in the coming expansion. And before your fire burns and cauldron bubbles, just remember that we're not even in beta yet and that a lot of things could change.