I'm not sure another person than one of the core Parrot hackers could pull this off, but Dan Sugalski has a piece on ONLamp on a real macho hacking expedition he took part in, in which a dated 4GL language was reimplemented in perl targeting parrot.
I can just imagine the meeting where the enthusiatic and confident Sugalski talked his boss into this. I am a firm believer in just trusting the hackers, especially in a situation like this where they chose to change as little as possible instead of reinventing everything. But Sugalski was really taking a bet on the parrot.