Hurricane Bill is what is called a "Cape Verde" hurricane because it formed near the Cape Verde Islands off the coast of Africa. Cape Verde storms are particularly dangerous because they can get quite powerful in the open Atlantic Ocean if conditions are right (Bill made it to the cusp of Category 4 intensity at its peak), and because they often curve northward as they cross the Atlantic, putting the U.S. east coast at risk.
In 1938, a classic Cape Verde storm struck eastern Long Island, killing 700 and destroying or damaging more than 55,000 structures.
One of the features of these hurricanes, seen with Bill, is the tendency to pick up speed as they turn north. Currently, Bill is off the Virginia coast moving at 24 mph. That's three times as fast as Katrina's approach to New Orleans, meaning there's one third the time to react. The 1938 storm was moving at an incredible speed of nearly 60 mph, meaning it could cover the distance from Cape Hatteras, NC to Long Island in a mere 12 hours.
Although Bill will miss the U.S. east coast, a turn of just a few degrees more to the west could easily have put it ashore anywhere between North Carolina and Maine. If the storm was curving as it approached the coast, the best the National Hurricane Center could probably do would be to issue a warning for several hundred miles of coastline, with relatively little time to prepare.
Needless to say, it's impossible to evacuate all coastal areas between Wilmington and Boston, or even half of that, so such forecasts are of limited utility.
If a category 3 or stronger storm like Bill--which is also quite large--were to approach the New York area (as happens with fictional Hurricane Nicole in my book Landstrike), it could wreak havoc, especially if it struck south of the city and sent a large storm surge up the Hudson River.
Sadly, most people along the Atlantic seaboard are ill-prepared for a major hurricane. Emergency management planners are well aware of the danger, and have made some plans, but their resources are quite limited in the face of apathy and ignorance among most residents, few of whom have ever faced a major hurricane.
While Bill will miss us, eventually one of Bill's siblings will strike. We should bolster the resources used to plan for such an eventuality now, before it's too late.