What would a 'Category 6' hurricane be like?

The Saffir-Simpson Hurricane Scale uses maximum sustained wind speeds to rate hurricanes -- and the possible level of damage they could inflict on communities. Right now, hurricanes are ranked on a five-point scale: Category 1, 74-95 mph winds; Category 2, 96-110 mph winds, Category 3, 111-129 mph winds, Category 4, 130-156 mph winds, and a Category 5, 157 mph winds or greater. Major hurricanes are considered to be category 3, 4, or 5. But, what would a "category 6" hurricane look like? Florida International University is testing the possibility.