I had the same situation a few weeks back only my flight was at 11:10.
Personally I don't think you'll have anything to worry about, but if you are concerned about making it, this is what we did:
We participated in the Express Disembarkation. The Sky actually docked at 7:00 even though it listed the docking time as 8:00. We were off the ship and grabbed a taxi and at the airport by 8:45! I would add another 40 minutes max to make it to FLL from Miami.
You don't have to register for the Express Disembarkation, but by all means check with the purser's desk during the cruise. You do have to carry your own bags through the ship the morning of disembarkation so DO NOT put them out in the hallway the night before.