Personally, I would like to see a longer span for the next contest; something akin to the spans in the original bridge builder, though perhaps not quite as long, as I don't know if it is possible to cross such a lengthy span given the new physics. I have a suspicion that a span any longer than the one for the first contest cannot be crossed by the monkey-bridge concept, or by the low arched roadway, and would thus provide room for more creativity.
I would like to see longer spans too. mabay with a really high water level or somthing.
I did not participate in the last contest and I do regret it so I would like to see a new contest soon.