I'd like to see something similar, an adapter that uses the raspberry pi as a daughter card. It could plug in the way a bridgeboard does and emulate a 486. It could also transparently provide access to the USB and network for the amiga side, or even memory. Or it could plug into the CPU slot, and emulate a 68k CPU upgrade or even a PowerPC.
I'm not sure if the gpio port is fast enough for CPU or memory usage by the amiga, but it should be fast enough for ethernet, usb, and disk.
brian
I have done everything except offer my first born for a RS232 card (PCIe in my case) so I could use AmigaOS in projects such as have been mentioned here. Nothing.
The only replies have been 'Nobody uses serial ports anymore'. Good thing Linux supports my hobby.