The official science isn't out yet on the explicit link between global warming and Hurricane Sandy, but we do know that warmer oceans make regular hurricanes into super hurricanes. From Climate Desk:
Warm oceans are jet fuel for hurricanes, so it's fair to say that these warmer temperatures are revving Sandy's engine. And while many factors shape sea surface temperatures in a given place, the overall trend—directly linked to climate change—is toward hotter oceans. Thus, while Sandy's particular path could be considered a matter of chance, the warm temperatures beneath it allows the storm to be stronger, for longer, than it might otherwise have been. And global warming is creating a world where, on average, those warm temperatures will be there more often than they were in the past.