Pasting here the announce directly from Katricia’s post on the official forums:
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.
The mechanics of the Auctions are still being created, however some details are available:
# Sellers will be able to place their items up for bid.
# Buyers will be able to search for items.
# Sellers will be able to set minimum prices on their items.
# Buyers will be able place bids on items.
# Item�s won will be delivered through the new in-game mail system for pickup.
Please stay tuned for future updates regarding Auction Houses and when they will be implemented in the game .We look forward to hearing your comments once they have been implemented.
Intelligent addiction copied straight from Final Fantasy XI.
It could be interesting because now you can really build some depth into the tradeskills, like the in/famous interdependence.
The players are already noticing problems about one of the features:
BB (or any other non-faction trade houses) will be the best/only place to trade.
And:
Will there be a kissing booth as well?
And people doubt me when I say the grouping/guild faction restrictions will end up getting yanked before release.
Suckers.