I agree 110% with Baby*Pink. I have done both. I went into NICU as a new grad because I had a definite passion for neonatal ICU. At the time, my plans were to continue to on and become an NNP. Along the way, I decided to pursue the CRNA route and after two years, switched to adult CVICU in order to get the best foundation for CRNA school (my plan is to do neonatal and pediatric anesthesia, so my NICU background definitely laid the foundation for my future).
I have to say that not much carried over from one specialty to the other. Obviously, I had learned to be a nurse in the NICU, so the basic nursing stuff was established, but as far as meds/skills/knowledge of disease processes, nothing was the same. When I left the NICU and went to the CVICU, I started an orientation just like a new grad (thankfully, mine was only 10 weeks instead of 24 weeks because I was an experienced ICU nurse already).
I would emphasize that the NICU is an environment that truly needs nurses that wholeheartedly WANT to be there. I would also guess that without the passion for NICU, few new grads would survive orientation -- you really, really have to want it in order to do it. And, if nothing else, the babies and their families deserve to have nurses with the passion to be there.
NICU is not for everybody...and there is no shame in that at all. But, if I were you, I would pass on the job and find something that you are at least interested in.