I would love to see (and pay a reasonable amount of money) for mount costumes.
I liked the way LotRO implemented the ways you can customize all the "armor" for their warsteeds.
ZOS, make it happen.
NA, PC Megaserver
Zhaani, Female Khajiit, Nightblade, AD (current main)
(Unless otherwise put in my sig, all characters are below level 50)