I understand that in all the cases confirmed in Florida thus far the virus was acquired abroad in one of the affected countries. So I would think at the moment it's still unlikely that the local mozzies there carry it and the risk is very low. How long it will be before they start carrying it I of course wouldn't know, not sure how quickly it spreads. I would think that the US is much better prepared to tackle it than most central and south american countries, and you get AC everywhere.
I've been following this closely as I have to travel to Florida for work next week. I don't think there's much risk, if any, but as I'm going there for work I'll be spending probably almost 100% of my time there indoors. I spent a week there for work in October and didn't get bitten and wasn't using a repellent at any point.