Blizzard finally decided to closed the auction house in 2014, and they released this piece of broken news not long ago. In the news, they explained the reason of doing so.
Auction house is designed to provide a secure and convenient trading system but the fact is it breaks the economic balance slowly. More and more players turn to rely on the AH instead of killing monsters to get powerful loot. Considering that, the development team determined to remove the gold and real-money auction house from Diablo III.
Loot 2.0 in reaper of souls will be the next system to satisfy players in the game. People need to farm nice equipment by themselves and enjoy the game fun in this way. Details of closing auction house are under discussion. The shutdown will occur on March 18, 2014. Josh Mosqueira will provide a video talking about this action later.