The other thing about the economy is that inflation will continue. Inflation is the increase of the amount of wow gold available to the playerbase. If you were to go add up all the wow gold on each player and each guild bank and compare it to that number in the last expansion, you'd see that it's considerably higher now than it was then. Monsters drop more money at level 85. And there are more players now than there were then who are looting more monsters. Quests reward a lot more money in this expansion. The definitely significant, source of inflation is that right now, 90% of the value of every stack of Obsidium Ore mined will end up coming from a vendor. If all products made out of raw ore had to be sold to players, it would be worth a lot less.
Sure, there are new wow gold sinks. Repair costs are higher, and the new vanity mounts cost more than ever. Still, in a couple of months, there will be a significant portion of the population that has access to less expensive for any vendor-based wow gold sinks. These sinks will slow inflation, but they don't balance it.