I think that any C&D is more likely to come from Cryptic, as they'd probably be more concerned about their engine being passed around the net than NCsoft would be about an unused IP being shared out.
Most likely, if NCSoft has any brains at all (which may be doubtful... but let's play 'let's pretend')...
NCSoft will allow servers to go up, and they'll allow people to get on board. The more the merrier. NCsoft knows that suing for the value of an outdated IP is going to get them minimal income. No, they'll wait.
Because for each and every person who plays on the system they can levy a valuation of lost revenue based on the illegal use of their IP. And then they'll valuate the actual IP as 80 million or so - whatever that insane offer was they through out there. And they'll say that all those people playing on the Emulator are proof that the IP has that potential, and use the actual logs against you to show they have been damaged. In this way, it's not just a question of 'did someone violate the law' but 'did they violate the law and were there damages'.
Then if they really want to be mean - then they'll drag NCSoft into it by listing them as a 'friendly party also damaged' and so on... they will demand damages, and so on.
That's how you'd do that if you're smart. If you're stupid, or you don't actually care, or if you just want to protect your IP then you issue a Cease and Desist. Because that's cheap - it's basically a letter from some guy you pay on retainer to send out the letter. Costs you basically nothing. Most people freak when they see something from a law firm and comply.
But, if your goal is to actually be evil and put a stop to something you don't just send a letter - you drop a legal nuke. For that you need to make sure you're going to win before you sue. The easiest way to do that is to prove damages in advance. Let's face it, if you're playing on an emulator they already have you red handed for using the IP without their permission. The hard part is getting the judge not to laugh you out of court for wasting everyone's time on a law suit no one gets anything from.