It is impossible to predict crowds...however no matter what day you go in the middle of summer it's usually packed.
With the addition of the waterpark, it takes away some of the crowd when it's really hot out, and that helps shorten lines.
However none of us have a magic 8-ball so we can't answer the question. I suggest looking in the Trip Report forum for reports from previous years, to see how crowded it was.
Go Bulls!
Dave - SFGAmWorld Webmaster