Today, Valve begins testing the new Steam Community Market, by using the now free-to-play shooter Team Fortress 2 as a platform for beta testing. What's all this, exactly?
The Community Market, in Valve's own words, is intended to "expand the Steam Economy beyond trading," namely by allowing players to buy and sell in-game items with others using Steam Wallet. So basically they're letting the community build their own economy, with real money and everything.
The trading system is already a major success on its own, and Valve counts that over half a million trades are carried out each week. Says Valve's Tony Paloma:
"Extending game economies beyond trades and giving players a way to turn gameplay into funds for new items and games is a key component for moving that success forward."
The Community Market will be extended to other Steam games following this holiday season. Bear in mind there's quite a bit of fine print to take in, like items being subject to transaction fees. An extensive FAQ on the official site covers some of these points.
Valve certainly hasn't slowed down with the new features. Just over a week ago, Big Picture officially launched on Steam.