There are two scenarios that may occur with Ike, and each are equally likely to happen:

Scenario 1 is that Ike turns to the west and misses the north coast of Cuba and tracks either through the Florida Straits or the lower Florida Keys as a upper end Category 3 to a Category 4 hurricane on Tuesday. After that, the extension of the ridge would erode allowing for a northwestward and then northerly track to potentially impact the west coast of Florida or the Florida Panhandle late next week.

Scenario 2 is that Ike tracks further south like the model guidance is trending towards and Ike tracks across northern Cuba or perhaps even over the entire length of the island. This track would knock the hurricane down from Category 3 or 4 strength to at most a Category 1 hurricane. After that, Ike would turn more northwestward and track through the Gulf of Mexico and strengthen slowly as its inner core could be severely disrupted by the island of Cuba. With Scenario 2, a landfall somewhere between Louisiana and the Texas coast would be more possible late next week as a Category 2 or perhaps a Category 3 hurricane.

I am going to go out on a limb here, and state that I am personally leaning more towards Scenario 1. The reason for this is because the operational GFS model's depiction of the 500 mb height has not been deep enough with the trough of low pressure in the Midwest and also the heights at 500 millibars over the southwest Atlantic have been higher than what the GFS model has been depicting. So, it is conceivable that the building ridge of high pressure may allow Ike to initially move slightly farther south than progged as it approaches the Turks and Caicos Islands and the Bahamas. Later on, the timing of the first shortwave trough, combined with a deeper Ike, could briefly cause a northward component to the track, allowing Ike to just miss Cuba and track through the Florida Straits or the southern Florida Keys as potentially a very strong hurricane. The latest indications are that tropical storm force winds will begin affecting the Florida Keys as early as Monday night.

It should be noted that it is way, way too early to be sure where on the Gulf Coast Ike could make landfall. That landfall possibility highly depends on the track of Ike over the next 2 to 3 days. If Ike tracks through the Florida Straits or the Florida Keys, then a landfall near the Florida Panhandle or the west coast of Florida would be more likely. However, if Ike tracks across Cuba, then a landfall further west in the Gulf of Mexico, from Louisiana to the Texas coast would be more likely.

I think that unless things change dramatically, you will not have to put up shutters.