Yeah I figure that framebuffer stuff would be a no-go at an early stage, that's why I was hoping for some kind of already-on character display!
Looking through the Rpi wiki page which discusses additional hardware it mentions that console output comes out via the UART by default at 115200 bps (ttyAMA0)...so at least someone's done that before! Looking through the Rpi kernel check-in there's code for programmable LEDs too, but it's not clear if that's just Linux support for LEDs attached to the GPIO.
I'm not savvy with the electronics side - would it be easy to hook up the eight GPIO pins to pick up this console output and turn it into something I can plug into a serial port? (to read on PC via a terminal program)