They will just keep NXT withdrawl disabled, no reason to shutdown the whole thing.
They already lost all their NXT. In fact, they have already sent 112 BTC to the hacker and only received 10% of the coins back. Unless the hacker plays nice guy and sends the rest of the NXT back just to be nice, they're done.
Seems like from a day when crypto coins were invited a hackers became very wealthy....
There is a reason why it is very dangerous ... we don't know what they will buy with their millions ...
A pro cyber police must be created.