Panic over nothing blizz stated SEVERAL times when the Diablo RMAH was announced that they will NOT ever add it to wow due to the economy already being established.
Give me a few and ill find the blues about it.
A new feature could be nearly anything but not this.
This is pure assumption and a foolish one at that.
---------- Post added 2013-02-02 at 08:40 PM ----------
Here is one place, its in the interviews
"This is specifically only a decent idea in our minds for Diablo III because an in-game advantage doesn't mean you steal a world first, or up your arena rating, or edge out in a competition. Diablo III is a co-op game. If you're buying power it's to jump into games and help your buddies kill demons faster, and guess what, they get more drops in less time. In our eyes that's not buying an advantage as a selfish measure, it's really just kicking more ass in co-op games with your friends. It's apples and oranges, if you will, to something like an in-game advantage in a game like World of Warcraft. "