WTF CAT 5 ALREADY???
Well, there might be some good in this. If past experience from this season proves useful, early strengthening like this usually means the storm will weaken before it hits land. We saw it with Katrina and with Rita. A storm can only get so big before eyewall replacement cycles begin and start eating away at the strongest part of the storm.
HOWEVER...Jeff Masters' blog at wunderground.com shows that the path of Wilma takes it over VERY WARM water that does not cool down until the Keys. Katrina and Rita both passed over cooler water for a full 24 hours--which helped weaken those storms. This may not happen with Wilma, so it may not weaken significantly before landfall. Mr. Masters hasn't updated his blog yet with the Cat 5 info...I s'pose he'll awaken tomorrow and sh*t his pants if its broken a record by then.