We were there last week and crowds were not bad at all. We arrived at park opening each day and all rides were walk-ons. As the day went on and we made our way back to our favorite attractions (Spider Man, Hulk, Mummy, Simpson's, Jurassic Park, etc.) for one last ride, wait times were 15-30 mins. The attractions that we spent the most time at (not necessarily because of the amount of people but due to how the que/pre-shows work) were Twister and Disaster.
I'm not sure how accurate it is, but you can find the wait times for each attraction here:
http://66.77.171.132/MobileWeb/ParkMenu.aspx