Someone mentioned the Parachute Drop (which incidentally prompted the "copy" thread), someone else (Uncle Bob I think) mentioned a Giant Victorian Balloon... why not combine these two?
Here is my thought. Rip out Maliboomer and place one large central tower (for all you old school fans place the Disney at the top). Then set up the stations to each have a vehicle themed to a hot air balloon. Taking the same concept as the Sun wheel, have 2 lines, one that has "plunging" balloons and another that has a much gentler drop for the little ones. It would have to be a well designed basket, nothing like the rickety metal cages of old. I was thinking more of a sit down style circular basket that would hold 8 people (think GRR). Each seat would have an individual belt, with a locking mechanism like Indy which would prevent the belt from being unbuckled, and prevent dispatch from sending the balloon without all belts safely secured. The actual balloons would be color coded depending on the coloring scheme of the actual tower. Have the gentle balloons one color, and the much faster balloons a second color.
If anything, it could be modeled to "Around the World in 80 Days". For the real purist, add a observation cabin to the center so it looks like Knott's, but designed a great deal better. I honestly think this could work. You could either take the balloon for the thrill, or enjoy a much gentler up/down and take in the view.
I open the floor.