We were there for Tropical Storm Ernesto last year. Between the hype about the storm and the fact that Northwest Airlines flight attendants were threatening to strike the night before we were scheduled to fly out, I was practically a basketcase the week before our trip.
Things worked out beautifully, though. We were able to fly out as scheduled AND get home (although I was much less concerned about *getting home*). The storm did hit while we were there, and we had planned to just hang out and relax at CSR when it hit. Last minute, my DH decided to go to MGM the day of the storm and just go back if it got too bad. It was GREAT...MGM was a ghost town, we toured in our ponchos all day, didn't have any lines at all, and it was possibly our best day of the trip. It got super windy and had pelting rain, but we just ducked into the shows and indoor attractions when the weather was at it's worst.
Not to mention, it was cooler than our previous August trips - still in the mid to upper eighties, but it was less muggy and not 95 degrees everyday.