My theory (and YMMV) is that NRE is not so much about the person you're with, as it is about your infatuation with yourself. You are suddenly attractive to someone, and loveable, and your self esteem shoots through the roof! But you've gotta get that fix, get that mutual admiration society started, and so you feel desperate for contact, in person, by email, by phone, whatever, just some affirmation that you are as wonderful as you have discovered that you are.
I'm not talking about solid, healthy self esteem, though, and doing things to consciously focus on healthy self esteem can help you feel less desperate for the new person.
I believe that NRE fades as you really get to know them, as you start to let yourself see them as complex people (with aspects you like and aspects you don't), and not just as a mirror for yourself.
That's my theory, anyway.