For a long time now, I have wanted an interface to connect a BeagleBone to a RAMPS board to control a 3D printer. Wouldn't you know, all I had to do was seriously start work on designing one, and a finished project would magically appear on Hack-a-Day:
This looks like a great board, and I hope to get one in soon for testing. The pinout looks to match the BeBoPr-Bridge setup, which means you should be able to run LinuxCNC from my MachineKit image straight "out-of-the-box".
One potential issue is the thermistors. The BeBoPr has a different resistor network arrangement than most 3D printer shields/capes (an actual network, vs. a simple pull-up resistor). It is reasonably easy to compensate for this in the temperature reading python code, but if you used this board without tweaking the temperature code, your temperatures would be precise but not be very accurate.
If you have one of these capes or are otherwise using LinuxCNC on the BeagleBone, please let me know.