The latest NOAA discussion notes that Hurricane Irene has weakened slightly, which is (quite obviously) good news.

However, the important word is "slightly".  For the next 12-24 hours, it probably won't change much in strength (either way) which means it will still have maximum winds as high as 105 mph.  Nothing to sneeze at.

By comparison, the Great New England Hurricane of 1938 was a Category 3.  This will only be Cat 1 when it hits New England.

For NYC:

...PROBABILITY OF TROPICAL STORM/HURRICANE CONDITIONS... THE CHANCE FOR HURRICANE CONDITIONS AT THIS TIME IS 4 TO 11 PERCENT. ALSO...THE CHANCE FOR TROPICAL STORM CONDITIONS AT THIS TIME IS UP TO 72 PERCENT. THIS REPRESENTS A GENERAL UPWARD TREND SINCE THE LAST FORECAST. THE ONSET OF TROPICAL STORM CONDITIONS COULD START AS EARLY AS SATURDAY NIGHT...AND HURRICANE CONDITIONS COULD ARRIVE AS EARLY AS SUNDAY MORNING.  ...STORM SURGE AND STORM TIDE... IT IS STILL TOO EARLY TO DETERMINE THE EXACT HEIGHTS OF COMBINED STORM SURGE AND TIDE WATERS FOR SPECIFIC LOCATIONS WITHIN THE FORECAST AREA TO BE CAUSED BY HURRICANE IRENE. MUCH DEPENDS ON THE PRECISE SIZE...INTENSITY AND TRACK OF THE SYSTEM AS IT APPROACHES THE COAST.  BASED ON THE FORECAST TRACK OF IRENE THERE IS POTENTIAL FOR SEVERAL FEET OF SURGE...PARTICULARLY IN WESTERN LONG ISLAND SOUND...NEW YORK HARBOR...AND THE BACK SHORE BAYS OF LONG ISLAND AND NEW YORK CITY. THESE TIDAL CONDITIONS WOULD BE EXACERBATED BY BATTERING SURF.  ...WINDS... AS HURRICANE IRENE MOVES CLOSER...THE THREAT FOR SUSTAINED HIGH WINDS IS LIKELY TO INCREASE. THE LATEST FORECAST IS FOR STRONG TROPICAL STORM FORCE TO HURRICANE FORCE WINDS FROM SUNDAY MORNING TO EARLY SUNDAY EVENING. TROPICAL STORM FORCE WINDS ARE CURRENTLY FORECAST TO BEGIN AFFECTING THE AREA SATURDAY NIGHT AFTER MIDNIGHT. A GENERAL CONCERN SHOULD BE FOR THE POSSIBILITY OF AT LEAST DAMAGING WINDS SOMEWHERE WITHIN THE AREA.  ...INLAND FLOODING... A FLOOD WATCH IS IN EFFECT FOR THE ENTIRE AREA. SEE LATEST FORECAST FOR LATEST INFORMATION. LISTEN FOR POSSIBLE FLOOD WARNINGS FOR YOUR LOCATION...AND BE READY TO ACT IF FLOODING RAINS OCCUR. 
Nate Silver thinks this could be a very expensive disaster for NYC.  Probably because of the storm surge.
 
For us here in Winston-Salem (central NC), it'll be almost nothing.  The real winds will be in New England, as the chart below shows.