An interesting twist to this, although technically not what he stated were the objectives, are tools like Phonegap and Titanium: you write HTML and JS that gets wrapped up in webkit and it works like a "real" Android (and iPhone) app. But as I said, nowhere near as low level as he wanted.
There is also a Ruby-based project but I can't remember its name.
There is also a Ruby-based project but I can't remember its name.