As interesting as this is, I'm not really sure what this gets you over a regular RTOS that might be used with these sorts of microcontrollers apart from easy po

As interesting as this is, I'm not really sure what this gets you over a regular RTOS that might be used with these sorts of microcontrollers apart from easy porting of existing unix software (though with 2.2BSD it would have to be very restricted in its use of syscalls - does it even have sockets?)