I miss LOTRO's outfit system, which had outfit slots for PVE which were not operable for PVP (so you could estimate your opponent's real gear). This may not work for PvP servers (or perhaps just don't let it work for any PvP area -- outside of starter worlds and so on). Costume panels were purchasable in the cash store, so you could have the holiday or seasonal outfits without cluttering your bank, and so on. Again not unique to LOTRO, and desireable for RP/story rich games.

I would love the ability to take the skin from one item and add it to a moddable outfit template for that slot. I would pay GOOD money in real currency for that -- it's a standard item in a number of games.