Once everything gets back online, there might be a panic sell, cause the price to plummet. But since bitcoins are the easiest way to get from mt gox to tradehill, there might be a panic buy as well.
This would be a weird scenario: prices on mt gox plummet to $5 while prices on tradehill soar to $40, but no one trusts mt gox enough to go there and buy. Hmmm