Is it still held by taunt?
Read Jorbles' post. If you target a taunt minion but it attacks the wrong enemy, that wrong enemy can a minion without taunt, or a stealthed minion, or even the enemy hero.
Being able to kill a stealthed auctioneer is cool.
I really, really like the design of the random attack minions. They seem like they're going to be really interesting to play with. Do you attack with them first, and then respond to the attack? Or do you attack with other minions first to try and eliminate the worse targets for the minions? The idea of cards that cause you to change plans mid-turn is sweet, and I don't think this is any exception.
I get that there are bad beats associated with this card (He failed to attack my 3 health opponent 4 turns in a row!!), but I love having cards like this in the game. Having to make multiple decisions in a turn, instead of one big decision at the start of the turn, is really fun and dynamic.
(Ogre Ninja also seems absolutely insane in arena. He's a 6/6 for 5 mana.. it hardly matters what he attacks, because he's bigger than everything else!)