This is great news !
Good luck to the developers involved.
Please dont over complicate this project.
Personally I would have :
Base no frills PPC motherboard, 1 GHZ, DDR3, PCI-e slots, mouse,kb.
Make base simplest possible so its dirt cheap to produce.
Then add everything extra as cards to fit in.
FPGA /68k + OCS chipset on a card
USB, ethernet ports on a card
If we have fixed specs on our cards and make drivers for them then other projects can reuse same cards and drivers for new systems.
Open source RTG drivers
The closest thing to open source GFX card could be getting data sheet for the Adreno 220 GPU, as used in qualcomm Snapdragon Arm processor.
Info and video of Adreno 220 GPU in action
[ Show youtube player ]