They saw a huge spike in attendance last season from opening Phase II and with the projected heat for this summer, I would imagine that will continue to be the case this summer as well. Sure wish OoF would get on board and aggressively expand.
Next season appears to be the "year of the waterpark" in our region again as Adventureland has already announced their expansion. SFStL will be announcing an expansion later on this summer. White Water in Branson is supposed to announce an expansion with at least one large ProSlide. I highly doubt Schlitterbahn is done expanding.