I am not sure if it counts as a repost when the original post didn't really have any proper reproduction method nor knew how the glitch fully worked, in any case, without Kaflaffel's thread I wouldn't have gotten this far.
Special thanks to Kaflaffel for putting me on the right track.
Netherwing ledge has been updated somehow, and it has introduced some very curious behaviour, first of all, helms are rendered on the Fel Orcs, creating cubes, second..
The Mount system is mildly damaged, normally when you enter, it saves the mount you were last on for your character, however, this has now been changed to save the mount that last entered the Ledge, what does this mean?, it means you can copy literally any mount you can ride. (Gyrocopters and Carpets requires their respective profession, if you try to copy those, you get the Netherdrake.)
This means that it is possible to get cross faction mounts.
Heres how to get a cross faction mount:
1. Get a friend with the mount you want.
2. Go to a place where you can easily get the Orc illusion.
3. Both of you relog.
4. Now, let the one that doesn't have the mount you want (The receiver) enter the zone with the illusion and then leave (So that you lose the illusion).
5. Now, the one with the mount(donator) should enter and leave.
6. The receiver should now enter and leave once, and voila, the receiver is now on the mount the donator was riding.
As proof, here is a screenshot of a Blue Dragonhawk on an Elf.
http://i49.tinypic.com/2j4dpv8.jpg
The mount is permanent until you are dismounted.