Will take till tomorrow evening, the bids/auctions tabs still need work and also some more testing.
Here's the new post tab:

And a long lost feature is back - you can now drag items to the auction slot again! (implemented in a way that will work with all inventory addons)
Also, in the search tab, a few new filters will be available. Maybe you've already seen it in the screenshots: max buyout price and max market price percentage.
There's also a discard modifier which will not list the auctions that match the query (to be used for scanning instead of
/aux scan)
Lastly there's a new way of specifying tooltip filters. This is the only filter that can't be fully done through the GUI form. You will be able to specify arbitrary combinations of filters with and/or/not in polish notation. For example a query for cloth armor which has stamina but neither int nor spirit would be "armor/cloth/and/stamina/and/not/intellect/not/spirit".
Someone requested a feature for scanning trade goods while excluding cloth. "trade goods/not/cloth" would do exactly that. Of course this being a non blizzard query you'd still have to scan all trade goods pages, but cloth wouldn't be listed.