It all starts with the polypack update: http://www.teamfortress.com/post.php?id=4410&p=1
Details on the FAQ here: http://www.teamfortress.com/mannconomy/FAQ/
Not only will players be able to purchase in-game items with real money, but modders will be able to profit from their items being sold in the game. I see great potential on this, and Valve never stops to amuse me.
I can just see this expanded into other valve games soon, as well as being offered as part of the steamworksplatform.
So what do you guys think?
I think it's pretty awesome if they keep it as is promised (you can still get everything the old-fashioned way). I see this has the potential to become a tool for indie developers who use steamworks to have yet another option for funding their games – if and when it gets offered like that.
I really appreciate the improvements Valve is putting on steam. Mac support, steamplay, the add-on feature on L4D2 and now this.