Nothing yet, sadly. Perhaps getting Retroarch to team up with an IPAC is trickier than I initially thought.
Since the cabinet was a christmas gift I had to get creative and went for a customized PC running Maximus Arcade on Win 7 =(
I will however give this another try on the next cabinet coming up! If this could be set up properly it will be the Shangri-La of cost efficiency =) The Pi is just a wonderful little thing!