Here's something to think about. Sandy is going to hit almost exclusively Blue states. It probably won't turn any of them Red, but, it will drive down turnout.
That means rather than X number of votes from those states, there are now X-1 votes, with 1 being how ever many people stay home.
The end result?
In terms of the electoral college, no change. Obama is still likely going to win the election with somewhere between 275 and 300 EVs.
However, in terms of popular vote, we could see something we've never seen before.
Romney has been neck and neck with Obama for weeks, but, Obama retains an EV lead. What this means is that Romney is sweeping Red areas while Obama is not sweeping the Blue areas. The end result of this alone could mean Romney wins the popular vote while Obama gets re-elected.
With this storm driving down turnout in blue areas, the chances of this increases.
This has happened two times before. Bush V Gore in 2000, and Hays V Tilden in the 1800s. Both times, the Democrat won the popular vote but the Republican won the election. This could well be the first time the opposite happens.