I presume the real money idea won't really get off the ground. You see, not all gamers are into business, trading and that whole tactic behind it. This is the case with most SINGLE PLAYER fanatics like myself.
I think you'd be surprised at the demographics. In fact there's even a few tough talking posters on these forums who own $25 rainbow WoW ponies and silly little paid for pets People like frilly little things they can buy in small chunks of their paycheck to fill that consumer need. Then there's the people who will try to tackle the higher difficulties but don't want to put in all of the work. They will likely line up to buy things in D3 whenever they meet a seemingly insurmountable obstacle, as it's a quick and easy bandaid for performance problems. Dunning-Kruger effect at its finest.
There's no question in my mind that it will get off the ground but how much can the third party sites can influence things? The Blizzard fees are pretty much indefensible, it's more a question of whether it will be enough to drive people to use third party sources again with the gold AH instead of the RMAH itself. Anyways it'll be interesting.