As others have said Fridays are much better than Saturdays. Don't get me wrong, there will be a lot of people. But from what I understand no where near as crazy as Saturday. We went last year on a Friday night that had PERFECT weather. We were able to hit up all the roller coasters (except Invertigo), Drop Tower, and three of the haunts. Not too shabby. It was our first trip to the Haunt and we had a blast.
The weather should keep KI from getting overly crowded this Friday night. Looks like the rain will be out of here by then, but still quite cool for this time of year.