Yesterday two guildmembers level 68 wanted to do this quest. As it turned out, it’s more of an event. Never done it before, weird enough, but it turned out to be a lot of fun. Our group makeup with shaman, pally, mage, rogue and mage was a bit odd, but we made it work with some help from a few folks who were also doing this event.
Basically you have to defeat five bosses in a row, especially the last one hits hard and once you think you’re done, he revives himself ;). And the rewards are great. As a non-70 you get a lot of xp and pots and bandages, plus a nice weapon at the end. As I did this with my 70 hunter, I got over 22g per quest, so the epic flyer got just a little bit closer.
More info can be found on the wowwiki and wowhead:
Chain starts with Brokentoe.