I would assume that in addition to security issues/fears of shopping at brick-and-mortar stores in the wake of the attacks, that people are also beginning to shop much earlier than they used to, knowing they'll get the best deal online, but need to make sure they'll get it delivered in time for the holidays.
I think enough media attention went to the fact that things sold out early or couldn't arrive in time last year that people are making early shopping a priority.
I've been watching one site with a number of products very carefully, and though the site owner hasn't told me any sales data (I should email and ask), there was a significant spike in October, and it's skyrocketed in November. Looks like people are seriously drilling down for obscure phrases as far as the 5th and 6th pages of results. The logs have been absolutely loaded this month.
It would probably be a good idea to add more products on the most popular, but I've suggested it and it's not up to me. If it were my own site I sure would.