I've been playing the Elder Scrolls Series for a long time and one of the most amazing thing always were the Mods where People could actually update, enhance and even change in a big manner all the look and feel of the game. Changing Game mechanics is something we dont want from a modder here, as it wouldnt work for an mmo. I am also aware that just allowing to change looks simply doesnt cut it as everyone would need to have that look. But:
How about implementing some kind of Armor/Weapon creator tool where people can actually custom create stuff and put it for display online and people can get started to vote, to get this stuff into the game craftable (or by finding, could be lore specific). I know this would be a hard feature to implement but this would make elder scrolls stand out of the crowd and i am pretty sure that a lot of people would love this game for that. Maybe you should give it a thought!