Right, there's a very small handful of them, a couple leather models and their recolors and an older, outdated mail model. He's referring to many NPCs in the game who have been given the one-pauldren appearance with plate armor or others that don't currently offer that option to players. Hell, there's even an NPC in the Alliance shrine (and I'm sure other places I've missed) that has mismatched pauldrens which looks awesome, but let's not get ahead of ourselves, lol.
Mountains rise in the distance stalwart as the stars, fading forever.
Roads ever weaving, soul ever seeking the hunter's mark.
I like all the ideas in the thread. Especially transmogging individual shoulders. Would open up a lot of possibilities. May not be the easiest thing to implement now though.