1. I don't want to warp anywhere to buy an item.
2. Price history. When putting an item for sale the default price is set based on price history average that the player can alter before accepting the up for sale-process. I want to see price history automatically when selling because otherwise I'd need to track it down via buy menu (a'la XI). It's tedious because I don't probably know the category of the item I'm selling.
3. Easy search for a specific item also for controller users.
4. Request an item and set a fee if somebody completes your request. (almost like real quests!)
5. Bigger screen-space for open menus. When I'm shopping I don't need to see 80% of the screen looking at an AH counter while I try to squint at the item names. This is currently really terrible in XIV!
Like all of that?!
If you really want to split hairs I'd be fine with you calling that a MW if it rocks your boat.
Then again I strongly suggest SE calls it an AH and it would be a great marketing tool to get some of the players back who left because of the MW disaster.