Later, Sandy will be going across the Gulf Stream. Surface waters are fairly warm - 7 or 8 degrees higher than usual for this time of year. Here's a buoy 150 nautical miles East of Cape Hatteras.
http://www.ndbc.noaa.gov/station_page.php?station=41001 Surface temperatures are still 79.9F (at the time I posted this.) Some strengthening can still occur. She's starting to wrap up her Southeast side, but she's too big to intensify the way small hurricanes can. In about a day, Sandy will officially be non-tropical, thus not officially a hurricane. However, that does NOT diminish the power of the storm a bit.
It's not just a nor-easter, as someone above alluded to - it's like a hurricane wrapped up in a nor-easter. Potential now of 10's of billions of dollars in damage. Let's say the value of losses is 50% of that of Katrina - yet people are downplaying this all over. The weather forecaster for Long Island is warning of gusts up to 100mph; yet a poll (on a weather related site for LI) shows that only 32% are making any preparations at all, and the majority are completely unconcerned.
But at least now, Bloomberg has closed NYC schools for tomorrow, and is evacuating the A areas.