Just hit exalted with Netherwing and I was screwing around since I knew what was coming, I mounted up and flew a little ways off the ground when Illidan came and did his spell on me.
http://img404.imageshack.us/img404/1549/illidanut3.jpg
When the dragon came to pick me up, he did not, and while Illidan cast his spell on me to make me move, my mount turned back into a grpyphon... I thought it was kinda funny looking then hearthed, when I did I noticed I still looked like a Fel Orc in shatt, had my buddy come look to see if I looked like one to him and I did as well, went to IF and got some attention...
http://img512.imageshack.us/img512/675/mountinifvg8.jpg
http://img404.imageshack.us/img404/3061/wootinifcy8.jpg
Don't know if I was just lucky or it can be duplicated, but it never hurts to try. =)