Mixing money and MMO's has always been a tricky business. Players are quick to accuse developers of trying to "sell power", a term that can blanket almost anything that is not a cosmetic effect. Regardless of your opinion of developers selling power it is a fact that it does increase the bottom line for a company as well as give players a way to further support the games they enjoy. For Free to Play games this can be its only lifeblood.
Diablo could very easily fall into the category of a no-subscription MMO. One of the only major differences between it and Guild Wars is that Guild Wars makes towns public areas. Other than that, you can play both without interacting with another person at all. Having an auction house is just one of the many things that MMO players just expect to have in their online games. A real money auction house takes things to a whole other level.
Let's first hash out the details of this: It will be a separate entity from the current Auction House, so you need to choose to use it. You are free to buy something on one AH and sell it on the other, meaning you can flip items for profit of gold or money. Furthermore, it will keep the fee of the normal AH, so you would need to pay a small, real money fee to Blizzard to sell it. From my understanding, they only deduct the fee if you actually sell the item, and for equipment the fee is $1.00 USD and commodities are a percentage based. There is more in-depth information here, but that is the short and long of it.
Blizzard introduced real money into their game, and gave players a way to buy power, but they are buying it from each other. This was enough to make many sit down and think. Generally, the blogging and gaming community has been against buying power in games, but buying it from other players is a different ballpark. Someone earned it, whether through luck or hard work, and decided he wanted something in return for that item he didn't want to use. If you want to enact that trade with real money, why shouldn't Blizzard provide that service in a safe manner?
Let's face it: People are still buying Diablo 2 character to this day. I just typed in "diablo 2 character selling" into Google and my 31.5 million results should be enough proof. (Note: Please don't click any of those links.) The market is there and thriving, so why not give the players what they want? They may not be willing to admit they want it, but the demand is there. Blizzard just chose to make it safe and reliable.
Though it may cater to the many people who can (or believe they can) make a profit off of buying low and selling high, the reality is that many of its users will use it like the Auction House we have today. The average smart player will sell a nice item, and then use that money to buy another item that is more useful to him or her. It is an extremely useful tool and side option to grinding gold in the game. As I mentioned above, equipment has a $1.00 selling fee attached to it, but I highly doubt that many items will be listed above 5 or 10 dollars. And the items that are listed will be ones worth buying, not garbage. Or just garbage masquerading as good items, but that is beside the point. You'll get your money's worth, and it won't break the bank.
Even more encouraging, the fact that Blizzard is doing this fee system can put players' minds at ease of the RMAH's intent. The servers to run Diablo are going to cost money to maintain, and the RMAH will solve that issue. It is a nickel and dime process, but it will keep the game running much better and longer than the money from the box sales will. More importantly, that excess money can go towards the company and developing an expansion pack or two. Starcraft 2 has its eye on two more installments and I am not counting Diablo 3 out of this one.
With this move, Blizzard has put together a system of introducing real money into a game that provides a benefit to its players, to the company, to the game, and puts its players minds at ease about the company's intentions. Blizzard is not trying to sell its players cheats to progress quicker: Every trade will be with another player who earned that item. Even buying gold won't be an issue, as I'm sure some items will circulate for the sole purpose of buying on the RMAH to sell on the standard AH for gold. A win for the players, a win for the company, and a loss for the gold sellers and bots. I don't see a reason not to support this move.
On another note, my Demon Hunter is having a really hard time keeping up the dark and brooding act while wearing bright pink, knee high boots, courtesy of the Auction House.