2 major factors play a big role in supporting that undesirable prediction. First Irene eye still is staying above water therefore like any storm it gathers strength as time goes by from the warm waters (although luckily at the same time water is getting colder as it goes north) but beleive it or not it would have been "better" if it it would have moved with its eye inland not in the sea. Any storm that already reached Hurricane classification has to be treated seriously to minimize problems. Dont fooled yourself by the Cat 1 or 2 numbers , it could be classified as Category 2 but its sustained winds could be very well so close to Cat 3 and also the wind burst is even stronger although for just a few seconds at a time. Coastal areas also are heavily affected by the sea surge or flooding and in many cases flooding its their biggest problem rather than the wind strength.
Second factor that seems not important but usually plays a big role on natural disasters is readiness, disasters history or if you will how accustomed people and emergency services in the area are used to this fenomena. People in Texas , Florida , Caribbean, Mexico and surroundings beleive it or not "are used to" or at least has learnt from past experiences therefore they tend to make better decisions , like evacuating, or not going out (lots of people get killied by flying objects) , not touching fallen cables or other common sense meassures. I do noth think areas as far North as New York are that well prepared. Even building codes are problably not enforced for Cat 4 hurricanes like in other areas.
I had been through several hurricanes back in Havana and beleive me you do not want to be in their path even for only a Cat 1 Hurricane (well technically , beleive it or not, the best place to be is the Eye of the hurricane ,is unbeleivable how calm the beach was after the hurricane and we used to jump into water for just a few minutes or maybe an hour, but the problem is you would have to be in its eye when it formed and follow its path for over a thousand miles and then only leave after it vanished completely). No matter how well prepared , how solid the building codes a hurricane with its slow motion , wide area, strong winds , heavy rain, sea surge or flooding, will keep you awake all night with its hauling even if you had not slept for days!.
Good luck is not the best advice, Secure your stuff and Leave and Stay out of way is the only advice at all.