WOTLK Servers: ADD AUCTION HOUSE TO DALARAN!
My suggestion is VERY SIMPLE and quite easy to implement.
Add an NPC to dalaran than allows access to the auction house. On the very first WOTLK server I've played on the AH was available in dalaran at the spot where the portal to wintergrasp would be (Horde side).
Benefits to this: Everybody could use the auction house without going out of their way, mage players wouldn't be trash talked, bashed, and flamed for not giving portals for free, and overall more activity in the auction houses would happen.