The biggest problem is the huge gap between the kinds of programs a kid can make vs. the kind he can easily download. When I was a kid the kind of programs you could type into a C64 were not that different than anything you might get, so you had an incentive to learn how to do that.
Using Scratch to control hardware could be a really appealing way for them to learn about programming.
> I have been helping my son learn about programming using Scratch.
As does Blockly (Google): http://www.gasolin.idv.tw/public/blockly/demos/blocklyduino/...
Blockly is easy to extend as well (maybe Waterbear is too; I have not tried).
Thanks for the work that went into this!
Kids will really enjoy something like this.