We were there July 7-14. I have only been to WDW in the summer months, and I can't say the parks were any more crowded than they've ever been. By using fastpass, the longest we had to wait for any ride was 25 minutes.
Last year, we went in early June, thinking we'd avoid some of the crowds. Well, in early June, the MK had Spectromagic and fireworks only on certain nights. So, when we went in to see those events, the park was jammed, jammed, jammed with people.
I do have to say it was really hot. It didn't rain every afternoon like we expected. In fact it only rained 3 of the 8 days were were there--two were brief showers like you'd expect and one rain event lasted several hours. Without that afternoon rain, it got really, really, hot and it didn't cool off much in the evening. Even with an afternoon swim break, we were feeling the heat by day's end.