They way the NEM network rewards people for keeping it ongoing requires nodes to keep some tokens on their wallets.
There is also Catapult, the evolution of the network which will introduce improvements that were done on the Mijin private blockchain project. Furthermore it is a complete rewrite of the original code.
By the way, NEM has zero lines of code shared with Nxt.
I am feeling very optimistic about this cryptocurrency, but I am not one of those who think that NEM is the real Bitcoin 2.0 crypto.