NEW ORLEANS -- Mid-Saturday morning, storm clouds are motorcycling across the sky. We're seeing, and feeling, the winds we've been hearing about for two days, the winds whipping the BP oil slick closer and closer to the shore of the coastal wetlands. And, after two or three months in which it seemed this city was virtually levitating (the Saints' victory in the Super Bowl, the forthcoming end of the Ray Nagin era), that sinking feeling is back, just at the time the city is reaching the climax of JazzFest. So, the talk among the locals is the dread that the regional economy and ecology is about to take another disastrous hit at the hands of outsiders, while the visitors are enjoying the music, the food, and the crafts that flow from the culture formed by that ecology. And there are reports of locals lining up for what many expect may be their last taste of raw Louisiana oysters for a long, long time. Frozen Chinese seafood, anyone?