Jagex is now making update after update based on what YOU want rather than what they think is best. These updates include the duel arena system, the auction house, and many more to come.
sorry its no auction house
its stated right here
Later in the month, we bring you the 'Grand Exchange'. This new building will be located in the north-west of Varrock and will house a huge new addition to the game: the ability to offer items to buy and sell across ALL servers and to ALL players! You might, for example, go to the Exchange and put a full Barrows set up for sale - then, playing Skullball in Canifis, you might get a message telling you that they have sold and that you can go to the nearest bank to receive payment! The Grand Exchange will allow you to spend more time on the things you enjoy, providing a less time-consuming alternative to selling your items on the Forums or amongst the crowds of Varrock Marketplace.