I predict the Mt. Gox trading starts at the roll-back price of around $17.5 BTC and tons of people who have lost faith in BTC over the incident attempt to sell their bitcoins at the new price (which is about $7 higher than bitcoins are currently selling for). The market will quickly self-correct, however, and within 2 hours, my prediction is that the price will be:
$12.72
They've reset the order book, and
bitcoincharts show's the best bid/ask at 12.50/13.00, but no trade, yet.