It's kinda amusing to read notes from Virtual Goods conference transcripts (via Scoble). When I was researching (ahem) World of Warcraft, I spent a lot of time at the Auction House trading to get a first-hand understanding of forces at work. I started trading common goods then uncommon goods, eventually trading rare and epic goods exclusively and cornering markets, dealing with server population age shift, taking advantage of migration surges, and riding the supply and demand cycle. I got so good at it and made so much gold that I started giving gold away to guild (We Know) mates, buying their mounts, paying for materials to help them build skills my guild needed and finally for MC outtings supplies. After I quit, my son was shocked that I erased all that gold off WoW's spinning disk plates. Unearned gold spoils the experience.
To do well at AH, one has to understand the in-game economy and player psychology intimately. But, apparently, participants of the Virtual Goods conference haven't invested much time into understanding the forces at work inside the virtual worlds, instead opting to project their understanding of Web 2.0 economy into close yet vastly different in-game environment.
WoW golds are not roses or virtual furnitures. They are more real because the needs are more real. Virtual goods they are talking about are words and desires expressed visually. In-game goods are more about tools, needs, respects, fashion, and…time. I have a lot more to say but, for now, I will say this:

It's like marriage, you have to live it to know it.

BTW, I think WoW has peaked and tiring fast. It'll take years to die though with so many people onboard.