Hi Eric, there's quite a few reasons, both real estate related, and personal
The cost of living in NJ is getting out of control, high r.e. taxes, high car insurance, high health insurance, and no signs of improvement in the future. NC's cost of living appears to be much more affordable, the climate much more mild, and in general, life seems to be just a bit more laid back.
NC seems to be an excellent position for growth - it appears to be a very desirable destination for retirees coming from the northeast, it appears to have a very diverse economy, and even though I'm sure it's seen its fair share of the building boom, it still looks like a good buy. My favorite thing to do is compare market rents to the cost of ownership. Areas like phoenix that were grossly overbuilt still seem to be upside down, why buy when you can rent for a fraction of the cost? The rents in NC look like they are still in line with home values. Not a steal for an investor to buy rentals, but not inflated either. I'm no pro, so this is just my observation, and I'd love for someone to question my thought logic and keep me on my toes!
Dan