The Diablo III auction house is about to be no more. While Blizzard disabled the ability to bid, buy or post new items for sale back in March, the auction house itself has stayed open, in order to allow players to retrieve any items bought or gold earned before the shutdown.
But if you have any stuff still lingering in the "completed" tab of the AH interface, now's the last chance to get it. As Blizzard reminds us, the auction house will disappear, for really-real, tomorrow. And then they'll be gone forever.