Wisdom of the Four Winds

Available from your flight trainers for 2500 gold, from the new capital cities in the Vale of Eternal Blossoms.

Since you guys upvoted me to the top, I might as well add all the useful information i can find (with credits to their respectful author of course).

Costs 2000 gold as a goblin.

Check the 'Taught By' tab above for the flight trainer's name and location for your faction.

Although questing is required to open the gates to the zone and enable questing/dailies in the area, the NPC that teaches you this skill is not phased even if you access the zone without questing at all.

Despite this site saying level 85, you need to be level 90. I just made it to Shrine of the 2 Moons as a lvl 86 hunter, but it says I need to be lvl 90.

Just so it is perfectly clear, there are no prerequisites for interacting with the trainers that teach this skill. Golden Lotus rep will reduce the cost of flight training and there is a quest line that leads you to the zone, but neither is necessary. You can get into the Vale by jumping off of the Serpent's Spine wall into the zone and running to the town (get onto the wall at the Shado Pan Fallback in Kun Lai Summit and head south a bit.) Until you start the Golden Lotus quests, there are very few mobs to avoid. The level 91 elite mob that you'll pass is completely avoidable if you stay close to the wall after jumping down into the Vale.