New Advisory Circular 21-45:
http://casa.gov.au/wcmswr/_assets/ma...tac21-45-1.pdf
The money quote:
8.4.3 Particular navigation packages that do not have a TSOA, but can be demonstrated to achieve the accuracy and integrity values required, may be acceptable to CASA.
So design something to c145 spec, but don't go through the full certification process and still get accepted? (In the same way VHF radios do not need to be TSO, just approved?)
That would be awesome for affordable ADS-B out for VFR aircraft.