Sandy may have lost its classification as a hurricane, but that doesn't mean that it's not an issue anymore. The storm is still capable of causing disruption, for average people, and for small businesses. The Wonder Forest put together a wonderful post of safety that I wish I had shared with you all sooner, but better late than never.
Businesses may well suffer. In fact, they probably will. Christmas is just around the corner, and while I am not bothered by a few gifts potentially turning up late, a lot of people, understandably, would be. So sales may well drop. Some sellers in the US may even have to temporarily close up shop. I know of a few Etsians who have.
But whether you are in the US or not, we could all be affected. There are likely to be shipping delays if you're shipping into or out of the US, so it would be wise to state somewhere on your website or shop that shipping delays may occur, and that you are not at fault, and that if something is needed urgently, they may want to find someone else who is closer to them.
This may even affect orders placed before the storm, especially if you were shipping into the US. I sent a package to the US a week and a half ago before I even heard about the storm, and it's been delayed - I can't say for certain if it's due to the storm, but it is a possibility.
I urge all store owners to make a point of announcing that shipments may be delayed, and perhaps get in touch with people you have recently shipped to who may be affected to let them know. Everything may be fine, but you never know.
Another point are custom made products that require frequent communication between the buyer and the seller. It is advisable that such sellers and buyers give their alternate a generous timespan in which to respond to messages if one or both are in affected areas, and that both remain patient. If you're in an area affected by the storm and you do a lot of custom work it would be advisable to mention that you may be out of immediate contact.
Yes, some of these actions may lose you a sale or two, by people who would be put off of perhaps having to wait a little longer than usual, but it is a natural disaster that you have to work around, and an informed customer is a happy customer.