I would doubt that Hurricane Sandy (if it were on Election Day) would be enough to prompt anyone to think a Presidential Election date should be changed.
But what about a massive Hurricane (like Katrina) or a truly massive Earthquake? Or some other large scale disaster.
Is there some legal mechanism to change the date of a Presidential Election?
First, the United States is a VERY big country-part of the reason why Federalism is the form of government (not Unitarianism like most of Europe); because the US is so large it is HIGHLY unlikely that a natural disaster would actually physically impact the entire US.
The Presidential election is held on the first Tuesday of November that is not the first day of November. The election of electors would not be delayed-at best there may be a court case that would very quickly get shot down (as in the day it was filed).