One of the things I liked about Wet'n'Wild was the music. I really don't want to listen to a 2 minute loop of some cheesy tropical music. WnW really set the mood well by playing some pop music. Sure, it wasn't always MY favorite song, but at least there was a lot of variety.
Also, Brainwash's soundtrack was brilliant.
I hope that WnW's upbeat vibe carries over to Volcano Bay.