After reading this article from Coaster-Nation, I'm pretty convinced a new launched Intamin water coaster is going to be built in the old Pilgrim's Plunge spot. Take all of this with a grain of salt, but the article includes an image of "leaked plans" and claims there have been some Intamin shipments to the area recently.
I took the image of "leaked plans" and placed it over a satellite image of the old Pilgrim's Plunge area, and it absolutely fits. Down to the old station, splashdown area...the paths and other rides in the park even match up (Notice the Kima Bay area, and Thunderbird element).
It does make sense... Holiday World could have gotten a good deal on this ride for the issues they had with Pilgrim's Plunge. "Hold On," "it will be a blast," "be the fastest to know", could all tie in to a worlds-fastest-launched-water-coaster. Also, as someone mentioned earlier, the socks could be a hint that you could ride it from the dry side as well.
I placed the "leaked plans" from the Coaster-Nation article over a satellite image of the park.