I would like to see cosmetic items for mounts to change their barding, breeching, and heraldic clothing. In fact, it would be nice to specify the house by heraldic embems that the horse could wear. This might require some difficult tools on the part of devs and artists. One could supply crude artistry tools within the game to allow players to modify items. Ooooh... and revenue stream possibilities. Oooooooooh!