hmm. I for one don't like to interact THAT much with other players. I had my share of trading, trade accounts, bartering and the always present feeling in the back of my brain that I'm getting ripped off. either because the item's a dupe or the player a scammer or the price is too high.
sure, it was nice to browse the trade forums (which lists all the items available for trade, just like an auction house would for example. wink.) and engage in trading. but you also had buyouts or fast trades and very little interaction with the seller.
in the end, I only did fast trades or gave my trade account details via PM. the difference to the AH in diablo 3 was the time it took to finally receive the item. I for one like the rmah in diablo 3, simply because me and my girlfriend got about 1.000 euros out of it in two months playing. it could have been more, but the game is rather boring.
the gold auction house is another thing. the inflation there (50 million gold - about 1.26€ or 2.26€, dunno, so good items only cost 1.5 billions up) is ridiculous, that is rather sad.