Behold - the simple trade improvement solution (and it doesn't even involve an Auction House! *GASP*)

When advertising in the already existing party search window, nothing much changes here except the little button at the bottom that allows people to open up a separate window, the "player shop" or whatever else it can be called. There may be other things added, I added a little counter in the popup that says how many items are listed.

When they click the button, they are brought here, as a separate window. It simply lists what they player wants to list, and they can whisper the person directly from the list, or close the window - that's it. There could be more functionality added, such as "drag-and-drop" items into the list and have them be automatically added. If this is implemented, then simply scrolling over the item can give a popup similar to what would normally popup if scrolled over in the inventory.

Editing the items would be a snap, popping up a small window with editable text, like so. Of course this would only appear for the seller. If the "drag-and-drop" is implemented, this window would be even simpler - only "delete" and "close" buttons would be needed.
Simple. Elegant. Useful as hell. I would kiss the ground everyone at Anet walks on if they could just do something like this. What do you think?