I have a feeling that when 1.6 comes out, horses will not be allowed in town like most other mobs. My suggestion is that aikar could do something with the java coding that let's horses (and their riders) to ride anywhere on emc. Or he Could add additional flags like horse* or horse_ride or even horse_saddle. You also will need to add donkey/mule chest flags.
DON"T Quickly erase the post before Volt sees it and does a "Grief the wild with Lava Walls so I can own all the horses."
One thing I think that should be added is the ability to take horse through the wild portals. Currently, you have to eggify all animals to get them between wild and town, but if you want to take your special horse to the wild for transportation, it would be a major pain.
Alright, you guys are pointing out the negatives of the first of many 1.6 snapshots. They will obviously fix most if not all of the bugs with horses.
I just saw that its possible to ride a horse and have a lead connected to a donkey at the same time, but I would love if there were carts that could be pulled by them!