How does Blizzard intend to keep a stable economy in WoW?
Blizzard will provide many ways for players to use excess money. Gambling, customizing your armour, building guild halls and other buildings, decorating those buildings, coloring your wardrobe, customizing weapons, care for mounts or pets, the price of chartering a boat or zepplin, repairing the durability of items, etc. In addition to these, vendors may offer high end items for sale or pay better for the items you sell back.