In the first hour of MoP Release, I passed by a few Adolescent Mushan in Valley of The Four Winds and skinned a couple of then. One "gave" me 9 Exotic leather, I noticed but gave no attention of it.
In the late morning, I passed by the same place again:
So here is the guide!
Preparation (If you are prepared, go to step 3):
1. Skinning 525, better with a skinning knife - ready for 86 level beasts.
2. Huge and empty bags. 2 x Trapper's Traveling Pack + Embersilk Bag recommended.
2a. For overpopulated servers (like mine) and with huge faction imbalance, you do NOT need any up-to-date gear for killing 86 level beasts or world PvP, we will only skin.
3. Go to the Entrance of Valley of The Four Winds zone
4. Skin all the dead Mushans, with the constant levelers income, they will kill a few for a quest and run away. The respawn, so far is instant!
5. Owning guild bank tab in high level guild or having maibox generating item is a plus - saving running to the nearby camp.
6. Profit! [Gaining at least 40+stacks + 10 stacks Prismatic Scale per hour - Exotic Leather stacks are going for 150-200g on my server, Prismatic Scales are over 300g]
Sha-Touched Leather can be converted to Exotic Leather while moving, so you could "fill" the wasting time.
After search in the Guides section, I found no thread regarding this spot, so lets spread the word!