We bought a Norfolk Island pine this year from Wal*Mart, it was originally from Costa Farms...?

My Mom got one, too. The problem is, they are nursery grown plants, they more than likely haven't seen outside yet. I would wait until Spring has sprung more (like when the temps are consistantly above freezing at night) and then "harden" the poor thing off. Basically, you expose the plant to the outside gradually over a 2 week time period. First for an hour or so in shade with little wind, then gradually extend the time in the shade, then move it into partial shade for a little while the next week, then put it out where you want it and see how it does. Keep watering it like you have been and give it fertilizer at 1/2 strength 2 weeks or so after its in its permanent home. You'll have to kind of play it by ear on if it will like it or even survive or not. Good Luck!!!