Many users have been reporting tonight problems at the auction houses across Azeroth. Those people experiencing the issue are finding that nothing is listed in the AH, or all of their items are gone without a trace. This problem has been going on for about six hours, and only appears to be affecting US realms.

Zorayn has posted that Blizzard is aware of the problem and their network technicians are working towards fixing it.

So sit back, have a glass of wine, and enjoy your Saturday night. Try not to use the AH, because finding all your stuff gone wouldn't be cool (you'll get it back though, I'm sure, if it is gone, one way or another).

We'll update this post when a resolution is announced.

Update: Rolling restarts are being issued to correct the problem. For servers which have been restarted, the issue appears corrected. The opening announcement on the loading screen makes note to say that no items will have been lost during this AH outage.