Quote from: Zarhym (Source)

Cataclysm – General
Q: Do you intend to have all 280% flying mounts scale to 310% when a 310% mount is earned, or will only purchased mounts do so?
A: Our current plan, is that in Cataclysm, you can learn a new rank of flying that lets all flying mounts move at 310% (even current 280% mounts). That will probably be as fast as mounts will ever get. We don’t like it that when you get a 310% mount that you stop using your old ones.
Q: If 310% speed is becoming trainable, does that mean we’ll be able to fly in Azeroth from the get-go?
A: We have considered the concept of  Old Weather Flying. Just kidding. More than likely, you’ll just be able to fly from the beginning.