World of Warcraft Gold (US) is a currency used in the US server as a medium of trade. WoW Gold, items are rewarded after killing the enemies. WoW gold is a limited resource and is hard to come by even though gold can be earned by various ways. It is still time intensive for any player to gather the gold needed to get better gears which make advancing easier. Because of the enormous need for WoW Gold, it has attracted many exploiters such as dupers and gold farmers. Arguing that they ruin other people's experience and enjoyment of the game, Blizzard has put up a strong fight to combat these exploiters by banning large number of accounts involved in the activities. However, there are as many players who would not want to invest their time and are willing to pay the extra money to get through the game. Generally, the price of WoW Gold in the EU servers are more expensive than those in the US.
Something to keep in mind as well is that this will make enchanting materials more valuable, since it is likely most players will now simply scrap their boe greens instead of getting them disenchanted. Also redundant dungeon/raid gear can be scrapped rather than traded to the (guild) enchanter in the run. Less stuff gets disenchanted, meaning there will be less ecnhanting materials, meaning their value will rise. All the more reason to DE rather than scrap as an ecnhanter.