EQ also only had 4 variations of armor for every race, nothing visually different, you had plate, mail, leather and cloth, and everything came with a pre-set "dye" to it already, then you applied your own hue. Wow armor is detailed, heavily, and wasn't pre-designed for this system either. Dyes would be nice, and they are in almost EVERY other mmo out there, even terrible warhammer online. But those games were designed with that in mind. I think from a programming perspective, you need to go almost right back to basics and start over to implement it.

I think the game has a TON of good armor in it already, although un-dyable, and if blizz could just give us a the appearance tab they have in LoTRo, or EQ2, where we have our stats armor on tab 1, and our appearance armor on tab 2(with the ability to toggle visible or not), you would find the game to be incredibly customizable. I have a few outfits in the bank just waiting for this, namely my fishing/archeology clothes, my wrath pvp armor, and a few tiers I prefer to current ones. (paladin T2, f-yeah)