When it comes to the RMAH, there is no solution that doesn't involve pain and maybe a great deal of it. Either the company loses (Blizzard) or the customers (Players) maybe even both.
What we should hope for is as little collateral damage as possible. If Blizzard decides to refund all RMAH translations they should do it quickly and quietly. Admit there was an error and apologize. Conversely extreme prejudice should be taken in punishing those who knowing participated in gold duping today. What they did was tantamount to fraud and as such they should be prosecuted to the fullest extent of the law.
This is a red letter day in the world of micro-transactions.
*Looks like we'll be needing a new tread.*