Thanks for the peace of mind. I too was contemplating returning for the D3200, but I'll be sticking with the D3100 that came in the mail today. While it looks like the D3200 is a nicer camera (as it should be since it is 2 years newer), the D3100 seems to be no slouch either. And you're right, the $130 price difference is 43% of the price I paid for the D3100 - that money could probably be better spent on another lens, extra battery, carrying case, etc.
I'm with you. I got the D3100 a couple weeks ago when the deal ran for $299 and I feel no need to drop an extra $130 for a camera that I don't feel is that much superior to the D3100.
I'd rather have the D3100, then buy the $99 lens 55-200mm that was on here the other day, and still have $30 leftover in my pocket for a memory card and case.