We were at OKW for Hurricane Wilma - let me ease your mind and say WDW is awesome when bad weather happens - we took a flight a day early as we were due in on the day before it was forecast, waited until SWA posted weather warnings, and they changed our flight to a day sooner no problem. We stayed at POP for a night on an AP rate, moved to OKW the day before the Hurricane was due to hit. That night, we received a memo and a phone call stating WDW transportation would be cancelled the next day, and please stay in your rooms - they played Disney movies on the resort channel all evening and day for the kids. Disney has its own hydro, so we weren't affected like the rest of Orlando. The hurricane came through early the next morning (we have photos of the trees blowing almost sideways outside our room). It was over in a few hours, and the sky was blue and sunny by noon. We received a message on our phone that the buses would be running to MK for resort guests only starting at 1pm, so off we went to an almost empty park! Crews were busy cleaning up debris as we travelled by on the bus. The news showed the damage and hydro was out in lots of places in Orlando, supplies were hard to get for a few days, but being at WDW we never even noticed there had been a hurricane except for a few branches down here and there. They're very good at hiding the 'real world' and keeping the magic in the forefront for guests! We felt very safe and well taken care of during the storm.
I don't think you will lose too many days of your vacation as long as you are already at OKW instead of being stuck in the airport.
Have a safe flight, and enjoy your time at WDW - be safe!