InBev is already rumored to be taking steps to control money in the BEC division knowing that companies don't want to spend upwards of $5 billion dollars with the economy in it's current state. They thought it would be an easy sell, but they didn't realize their own stock would fall faster than Sheikra does on it's first drop with the world's economy right after.
Will they close the parks? Only if they're stupid and have their brains sucked out by aliens! The parks are a profitable group. SeaWorld Orlando is opening the only flying coaster in the state in a few months, so that will be a huge draw as well as the aquarium themeing that non riders can enjoy.
Sea World and Busch Gardens do a great job of getting locals and/or people in the "day drive" markets to come to the parks a lot with the Florida Fun Pass where you pay for a day and get the rest of the year free. It's the best deal going in town, and many people take advantage of it. When they do this, they spend money in the park, where the parks make their money, so sales are always strong with these passes, even in poor economy times as we're in. They started doing this after the September 11 attacks with tourism dropping then, and they survived. The parks even kept Anheuser Busch in the black when their watered down beers weren't selling well a few years back, so they are a proven money maker, but only if the InBev penny pinching doesn't hurt the operation.