For those of you who are busy toiling away for Netherwing Rep. I noticed today that if you fly in and out of areas that cause you to "wear" the Netherwing disguise there is a small chance that it will take the disguise off of you and leave it on your mount.
Cliff Notes:
1) Fly in and out of Netherwing Areas (Cause you to wear disguise)
2) There may be a chance that lets you keep the disguise on your mount.
3) Fly anywhere (Pic of me in Shattrath; Shows my current rep, and the tooltip for the Dragonmaw Buff).
4) The disguise will stay until you dismount or go back to Netherwing Ledge.