Valve has launched the beta for its Steam Community Market, a new feature of the service which allows users to buy and sell in-game items for Steam Wallet funds. Currently, only Team Fortress 2 consumables and tools (e.g., paints, keys, and crates) are applicable, but other games will be supported "in the New Year."
While I'm glad that it exists, the whole economy component of Team Fortress 2 has never been something I've desired to be a part of, and I'm equally glad that the game can be enjoyed without it. For those of you who are looking to make some money on keys and crates, I'll kindly point you to Valve's FAQ for the Community Market.
The main highlight is that, yes, the company takes a cut -- a 15 percent transaction fee during this beta period that gets paid by the purchaser. Interestingly, there's also a 200-sale limit per calendar year that begins on January 1. It'll be interesting to see how some of this stuff evolves over time based on user feedback.