How to get to the top floor of the Auction House in Stormwind
Head over to the Trade District, go to the westernmost tunnel, which, if you went through it would take you to the Mage Quarter. Don't go through it. Face the tunnel, but still be in the Trade District. Look to your right, you should see a crate with a barrel on either side of it. Jump onto the crate in the middle. Face the flaming torch in the wall, jump onto it. Then jump onto the wall next to the arch. Don not go through the wall, otherwise you'll have to start again. Instead face towards the arch and jump onto it. Then run towards the top of the arch. Once you can't run any more, stop. Then use your mount. This should make you go through an invisible roof, then run to the very top of the arch. Once you reach the top face the auction house, and dismount. Then run towards the auction house, but do not stop running until you are inside, otherwise you will fall. When you are in the auction house you will be on a support beam near the roof, you can stay here if you like, but, if you want to get to the top floor, simply turn to the right and jump onto it.
I have made a macro for the General Chat, it proclaims my achievement of getting here.
Added by: Moynihan Aug 29th 2010, ID#15322