I'd second this suggestion. I love the idea of using ruby on ios, this looks like a womderful solution, and it looks far more rubyish in syntax than Mobiruby (which isn't there yet anyway), but I would really like to try it out for myself in the simulator and develop a few simple apps before deciding whether I would want to use it professionally. If they could limit it to simulator only for free it would be much easier to tell if it is going to be really useful or more painful than just putting up with obj c. Having a demo might even boost adoption.

A question for the developers - did you consider this option and reject it for some reason?