Banwave happened for AH tycoons
There are reports of AH moguls getting banned for flipping the RMAH. Supposedly using bots and not normal traders. People are making $1000/$2000 dollars from this, so not sure banning them really has an effect. They can buy 10 new copies and continue right away with auto hot key scripts looking for things to flip.
Personally hate this part of the game, because of the RMAH people dont care about their accounts. Simply flip as much as possible and start over again when you get banned. There is no official statement so far, hope they give one.