World of Warcraft's Trading Post has flung open its doors today (though not literally, because it's a stall and thus doesn't actually have doors), letting the citizens of Orgrimmar and Stormwind do a bit of shopping. The Trading Post sells cosmetic items, some of which were previously only available for real cash, which will be refreshed monthly.
The good news is that simply by logging in and taking a brief tour of the shop you'll have enough of the new currency, Trader's Tender, to clear it out...