While doing the quest in Auridon where you train for the Veiled Heritance (undercover) and you have to race around the island, my friend and I got the idea that it could be rather fun to have an obstacle course like that somewhere where you could race against other players. Although you can train your horse in speed and stamina, I don't think that would be the simple determining factor, because it would also depend a lot on your ability to stay on the right path and jump at the right time (as we learned while doing that quest, running up narrow planks isn't always easy). It seems like it could be fun for role playing and having a friendly challenge between friends or guild-mates. The key would be having an NPC that initiates the official race (either after talking to them or just on a regular cycle), where you have a certain amount of time to get into position and then a barrier drops and you can go. Perhaps there could be some little miscellaneous achievement for winning a certain number of races or something. I know it's just a little mini-game sort of thing, but I thought it might be fun anyway.