National Public Radio ran a story about players paying real money for virtual goods and characters the other day. There's an accompanying text story at the NPR website which is rather mundane, but the broadcast story is much more in depth and interesting, including claims that sales of gold and items is a $200M - $1B yearly industry.
The story is broad but it does tend to focus on WoW, probably because NPR's game reviewer plays WoW"every day, sometimes for three hours a day". He's in a guild named Pirates of the Cove so a wave of the hand to his fellow guildies from NPR.
The story both reports and editorializes, coming down on the side of getting your stuff the old fashioned way: "For me, the point of playing these games is not to win -- it's to be immersed in the worlds, and to interact with fellow players. You miss out on truly experiencing the world if you don't earn your items and character abilities."
If you go to the story you can hear a replay of the broadcast. It's worth a listen. You can even hear the commentators talking about the game and getting interrupted when one of them has to fight a mob in the game. He gets nearly two silver from it!