What they did was destroyed the reputation of Mt. Gox - I don't think the Gox people will have a very good outcome as their customers jump ship to other exchanges.
BUT on the other hand, you could say Mt. Gox was asking for it with such poor security measures. A day ago, it was a CSRF hack ... and today it's a database dump.
I tell ya, tomorrow, the code for their trading platform will hit the net.
In fact, I wouldn't put it past the operators of the other exchanges to perpetrate something like this.
In reality, no damage to the bitcoin network was done, but Mt.Gox ended up with egg on their face.
Where will all the trades go? To other bitcoin exchanges - and there goes the services charges too. There's a sizable amount of money to be made by taking down Mt. Gox.