I've heard conflicting reports about crowd levels in Disney parks this summer. This morning I read that it was not crowded yesterday in the Magic Kingdom. Now while everyone's idea of crowded may be different, my experience with August crowds has been that they it's busy but not terribly crowded. I always chose August because some of the schools in the south begin in early August, leaving the parks much more managable.
But if you read Disney's quarterly earnings report (http://corporate.disney.go.com/investors/quarterly_earnings.html), they're not experiencing a lack of visitors to Disney due to the economy.
The only time in August (and early September) that I expect it will be very crowded is for Disney's free dining. A lot of people take advantage of dining on Disney for free. We did this in 2006 and in a week, we racked up $1,300 in disney dining that we got for free just for booking through Disney during a specified time period. That year, we were there Aug. 14-21. Now they've pushed the dates back to Aug. 22, making it impossible for those of us with school and college-age children to take advantage of the free plan. My guess is (from a cost-effective standpoint) Disney would rather have 2 adults and 2 children under 5 utilizing their free dining plan rather than 2 adults and 2 hungry teenagers taking advantage of it!
And though it was great eating at some of the best restaurants Disney has to offer for free, the crowd levels in the parks were much higher that year.
It's nice to dine for free but I'd rather have less crowded parks!