After the rolling server restarts on October 24, 2009 the Auction House was returning an Internal Error and was inaccessible. However once the Auction House became available ALL of the auctions were gone.
Most likely everyone will be receiving their inventory back in the mail within 24-48 hours (not sure how they are going to reimburse lost deposit fees)
In the meantime, multiple sections of the AH market are left without any inventory! quickly fill up the market and post at 50-200% mark ups over normal prices.
This is a better time than any to reap in large profits if you’ve been dealing with a lot of competition or have anything sitting around to unload in the auction house.
Also be aware that as everyone begins to fill the auction house back up with supply, all that lost inventory floating around the internet will eventually be returned to everyone’s mailbox, they will then post them all on the AH (a whole server’s worth of stuff) and I suspect we’ll see the exact opposite and an OVER supply of the AH and you can buy up anything undervalued as prices will return to normal within a few days.
I'm not sure if I'm angry that I lost 2-5k gold that I had tied up in the AH or that I'm going to make it back by overpricing things…