I'm not aware of new regs on the horizon for test pilots (assuming this is limited to amateur experimental). For certified aircraft under part 21.37 calls for:
21.37 Flight test pilot.
Each applicant for a normal, utility, acrobatic, commuter, or transport category aircraft type certificate must provide a person holding an appropriate pilot certificate to make the flight tests required by this part.
However, there are also Designated Engineering Representative (DER) Test Pilots who are authorized to determine compliance with FARs on behalf of the FAA. I can't see FAA flowing this requirement to the home built world. The requirement to become a DER test pilot is much higher and is contained in the designee management handbook: