One thing too look at is the arc that is listed in the forecast. If you are within that arc, you should consider it being targeted on you. I think a lot of people concentrate on the line. Anything within the arc could reasonably happen.
Irene was an example of a storm flying out of the arc. It was horrible forecasting. I think once Charley finishes his interactions with Cuba, we should get a much more accurate idea on how this will all fall out. For now, if you are in or near the forecast arc, you should take the precautions you deem nessecary.