I according to the database there are a number of mounts you can acquire in the game that have a speed of 280 (the same as the preorder lion).

My question where do you get these mounts? I have only found 1 mount which is in Valika and has a speed of 270.

http://www.teratome.com/search/riding%20skill#items;sort:reqlevel,name

mounts are either preorder bonuses or rewards from things like nexus or reputation quests