Heard back from two of the four people I'm working with. Everyone has just been busy with other things, probably more important things. Myself included.
I want to spend all weekend trying new stuff with the engine, and finding a "safe" limit to number of Chipmunk-js bodies and constraints for iPhone 4S. There are some puzzle concepts I'd like to experiment with, at the very least to rule them out "early". We'll see how that goes!