If you were to install the PTR right now and try to post a batch of auctions for sale with your favorite addon, there's a good chance it wouldn't work. Blizzard has changed the way that addons can interact with the auction house so that it's no longer possible to queue up a large volume of auctions and let them post while you read my columns.
Both Auctioneer and Quickauctions 3 have been hit hard, obviously. These are the most commonly used addons for queuing up a bunch of auctions. The rule previously seemed to be that we're not allowed to buy in batches, but we are allowed to sell in batches. Well, it looks like Blizzard has decided that we can no longer sell in batches, either. In addition, QA3 has lost its ability to automatically cancel auctions that have been undercut. The new patch requires a hardware event per action, and this has not (at the time of publishing) been written into these addons.
So what is a batch? Since you can queue up multiple stacks of the same item using the default UI, that seems to be allowed still. What is no longer allowed is putting together a list of different types of items that you want to sell at the same time. Take heart, dear reader: There is a workaround!