You asked for it and the development team has been working hard to get an initial implementation of the Auction House ready for testing!

An Auction House will be placed in each major city (Stormwind, Ironforge, Darnassus, Ogrimmar, Thunderbluff and Undercity). These Auction Houses will be faction specific, allowing Alliance to trade with Alliance and Horde to trade with Horde. Additionally, there will be one non-faction based Auction House in Booty Bay. The Booty Bay Auction House will have the same functionality as the aforementioned faction based Auction Houses, with the additional capability of allowing trade between Horde and Alliance characters.