With all the advances in OBSE an modding, there's a great opportunity for someone to take up the challenges of an advanced horsemanship mod, combining a number of elements and introducing a new actor value skill of Horsemanship with mastery perks.
Your Horsemanship skill would improve the more you ride, and there could be NPC trainers at stables to train you for cash.
Based on your skill in Horsemanship, it will determine how well the horse will obey your commands, how fast you can go without flying off the saddle, and at more advanced stages engage in magical combat (journeyman), melee combat (expert) and mounted archery (master).
Your skill can also account for how well you can steal a horse. As a novice, if you try to steal a horse it would likely buck you off after a short while (the higher the skill level, the longer you stay on), but an Apprentice would be able to handle it without problems.
Simple horse commands would only be available for Novices, and as mastery increases, more complex commands would be availble including commanding the horse to attack/not attack.
Thoughts?