Hmmm, looks like some new PCBs arrived today. I only ordered 6 but it looks like they included 12. Apparently I need to read the fine print.
These PCBs are to make it easier to hook a Dexter rev2 prototype board up to a Rasperry Pi. I estimated that 6 of the 10 prototype owners may want one but it looks like there is now enough for everyone to have one if they want. I will be soldering mine up soon as I have already ordered the parts.