Latest recon shows an open eyewall again, but pressure down to 965 mb and maximum flight level winds of 100 kts, which would correspond to 90 kts ( ~ 105 mph) at the surface.

Dean appears very likely to evolve into a major hurricane. As OUShawn alluded to, it is unusual for strong hurricanes to be moving so quickly, but in this case it is simply due to unusually strong steering currents. Most fast-moving tropical systems that struggle do so because there is a lot of shear in the environment, but that isn't really the case here (though the rapid movement has helped to exacerbate some slight westerly shear so far).

The fast movement also comes into play down the line... if it does end up hitting the Yucatan, it will spend less time over land than most storms would in that scenario, leading to less weakening and a stronger hurricane to worry about downstream when it enters the Gulf (compared to what you would normally have with a Yucatan landfall scenario).