I certainly hope DY don't set up a base at NCL. They'll just undercut the current airlines operating routes, who will pull out, leaving DY without competition so they will increase prices. The jobs they provide will be low paid and unstable.
I agree that Baby were cheap. But look where that got them. TK can bring little to us that BA/KL/AF/EK/LH bring us with flights via their respective hubs. Yes they fly to Iraq/Afgha/Rural Turkey but I can't imagine there's enough demand to operate the route from NCL.