To me, this isn't a test of the horses, but of the riders. They switch out horses every 40 km for a 1000 km trek through the Mongolian outback -- um, what part of Mongolia isn't outback???
I don't think I would do this, but maaaayyyyybe I would, if I was single, no kids...
The Mongol Derby 2012 is over | The Adventurists
While you're there, check out the other adventure trips. Way cool. I would totally do the Mongol Rally!