Blizzard have announced that they will soon be adding a new in-game item called the WoW Token. These will allow players to simply and securely exchange gold and game time between each other.
Players will be able to purchase a WoW Token through the in-game Shop for real money, and then sell it on the Auction House for gold at the current market price. When a player buys a WoW Token from the Auction House for gold, the Token becomes Soulbound, and the player can then redeem it for 30 days of game time.
Blizzard say that the WoW Token was created to give players with lots of extra gold the option to use it to help cover their subscription cost, and give those who want to purchase gold a way to do so from fellow players through a secure, easy-to-use system.
The WoW Token will be making its debut in an upcoming patch—in the meantime, check out the official WoW Token FAQ for more details.