Okay, so earlier on the PTR i was PvPing, killing alliance and w/e I usually do. Then i saw a Blood Elf Pally fly by me very fast on his epic mount and was Wtf!!?? Haxxors!
So I thought I'd try to figure it out by myself and well...I did!
You need to be a Paladin as far as i know. This could possible work with [Riding Crop]. But what you need to do is:
First Cast Crusader Aura.
Next Mount up on any 100% Land Mount.
Third just simply log out and back in. You will be going about twice as fast if you start moving when you log back in but i prefer log out and back in twice.
Keep going around 150-200% speed as long as your mounted.
You can possibly try the same thing with Riding Crop if you manage to get one. Equip it, mount up, log out and back in etc.
Note: This only works on the 2.2 PTR!