So the announcement that in Diablo III players will be able to buy any item in the game from other players for either in-game currency or real money caused some heads to explode and people to discuss the evil of "pay to win". Apparently nobody noticed, or at least chose to keep mum about, the fact that this is exactly like EVE Online. And the EVE fans have claimed for years that this isn't evil RMT, because you buy the items from other players, not from the game company. As usual MMO commentary is highly tribal, thus if one person's favorite game company does something it is a force of good, while if another game company does exactly the same it is a force of evil.
Nevertheless I find the system in Diablo III interesting, because it is safe to assume that a lot more people will play Diablo III than EVE. The more people participate in a market, the closer the actual prices on the market reflect what could be called the "true value". And I think this true value will be an eye-opener. And that is a good thing.
One of the curses of current games is that players often have a very unrealistic idea of the "value" of their virtual achievements and items. You might think that it is okay if people value virtual stuff however they like, but ultimately it is leading to stories like this Chinese couple selling their children to finance their online games. How we spend our time and money in online games *does* have some effect on the real world. The more common story is a student failing his exam due having played instead of studying, but even there it is obvious that the player got his priorities wrong.
By putting a realistic price tag on virtual items, Diablo III will give you a clearer idea of what this virtual stuff really is worth. Failing your exam to get hold of the Sword of Uberness might feel totally worth it initially. But once you see that same Sword of Uberness on the auction house for $5, you might reconsider. Some commenter complained about this "cheapening" your virtual achievements, but in fact it only tells you their true value, which wasn't much to begin with and you just totally overestimated it.
Virtual items in MMORPGs can usually be acquired by spending time. The auction house will put an hourly dollar value on that time. And this hourly dollar value will be significantly lower than minimum wage. Not just because the famous "Chinese gold farmer" might want to earn US/European minimum wages which are a fortune for him. But also because many players don't consider playing a game to be work. They'd do it for free, or even pay for the privilege. So getting paid cents for the hour is a great deal for these people, as long as they just sell the stuff they found while having fun playing. Lucky random drops might distort the image, but in the long run your virtual "work" is only worth cents to the hour. Let us hope that the Diablo III auction house will make more people realize this.