If this follows the pattern of the Snow/Wind storm that hit Seattle over the winter of 2006-2007, about one month after the power comes back on people will be selling their generators for half price on Craigslist.
I would expect gouging to exacerbate this -- people will want to recover some of the money they spent too much of.
I know this sucks for people in New Hampshire, but if Home Depot weren't allowed to raise prices you would not have people driving truckloads of generators in to meet demand. Plentiful and expensive generators are better than fairly priced generators that have completely run out. It's the beauty of the market.
Having said that, yes, it does suck that people in New Hampshire are being charged extra for generators, and I'd probably be pissed too.