These are, essentially, man-made noctilucent clouds (NLCs). Water vapor in the exhaust of the rocket crystallized in the high atmosphere, creating an icy cloud that turned blue when it was hit by the rays of the morning sun. Years ago, space shuttle launches produced similar displays.
Natural NLCs form around Earth's poles when water vapor in the mesospherecrystalizes around meteor smoke. Sometimes they spread as far south as Colorado and Utah, but rarely or never Florida. Electric-blue over the Sunshine State requires a rocket launch, and that's what happened today. Browse the realtime photo gallery for more images of the Falcon 9 launch: