Simple and amusing exploit. Only usable at 70 and in outland ( not instances or indoors)

Whilst on your flying mount (Epic or normal) and on the ground, get a mage friend to first Frost nova you, then Frostbolt, Then Polymorph. Break it with a frostbolt and if done properly you should still have the mounted buff though no longer be on your mount due to poly. From here you can take off through the air as if it is water, effectivly swimming through it.

You can attack in pve and pve from the air.
Mobs will not aggro though will take damage and die
These mobs will not be lootable
Known reportable exploit, use at your own risk
Mounting, logging or entering a house or instance etc will remove the buff

I assume this works beause flying mount has no script to remove the flight buff if polymorphed seeming as you are supposed to be immune, but whilst landed you can be sheeped, with no script the buff does therefore not disable even though you are dismounted.