This is a good question. We should always be asking what we can offer the other party to help them get what they want.

I have heard that the ZeroCoin people were a little miffed that after they found a way to bring anonymity to Bitcoin, they realized that their solution would never see the light of day. The Bitcoin Devs are just too conservative with a $10 B market cap at stake...they can't afford any more screwups, so they are extra cautious.

So maybe we can tell ZeroCoin that we are happy to help them implement their solution into our blockchain, and they can also proceed with their Bitcoin fork that implements ZeroCoin.

This would show the practical versatility of their solution and give them academic bragging rights. At that point, Zerocoin would have been implemented in both a 100% PoW Bitcoin fork, and also implemented in the 100% PoS Nxt invention.

"Our truly anonymous ZeroCoin protocol has not only launched its own currency, it's also been successfully implemented into Nxt, the first 2nd generation cryptocurrency."

This would be huge news in the cryptocoin scene and would bring a lot of prestige to both Nxt and ZeroCoin.

We should also offer them a respectable bounty and let them choose to take it in Nxt or BTC or some combination of the two. If they want BTC, then we can hold a sale on the forums like they did to raise money for the cryptographic audit. I think it would be a mistake to try to shove NXT down their throats if they prefer bitcoins instead.