Or the gox coins are moving to their new owners (takeover rumors true)?
And the new owners are playing Satoshi Dice.
Its rather siphoning of coins in progress..
And thieves would send some of that btc back to other gox addresses why exactly? Do you even realize how large this volume of coins is?
You'd be playing quite a lot of satoshi dice to get anywhere at all. I'm not saying that trying to mix such an amount is futile but there is quite a large probability that you'd leave enough of a paper trail to be caught