This model data shows a similar scenario and outcome with Hurricane Sandy for the Mid-Atlantic and Northeast (i.e.: Washington D.C., Philadelphia, all of New Jersey, New York City, and Boston, for Monday through Wednesday... )
Sandy will become "extra-tropical" in the next 48 hours, and will transition into more of a "Nor'Easter". The transition to this is by no means a reason to think that the storm is in a weakened state. In fact, the storm is expected to intensify by Sunday into a large, windy, wet, and "deep" weather system, and will approach the above areas by Monday. There remains differences as to where the location of landfall will be, but the point of this location does not diminish the effects that the Northeast will feel -- and are slowly becoming clearer, and will be detailed tonight or tomorrow.