Old Akro,
WAAS requires specific satellite signals.
WAAS requires aircraft GPS receivers that are WAAS capable.
WAAS requires a small network of ground stations to broadcast correction signal to achieve "WAAS" accuracy, the aircraft does not need to "see" any ground station.
Japanese satellites cover Australia with a WAAS signal, this is a different satellite system to the original over the central Pacific, which was moved when the Australian policy decision to not deploy WAAS was made public.
The value of WAAS, for other than aviation, is rapidly declining, as Generation 3 GPS goes into place, providing positioning accuracy equivalent to WAAS, without the ground based infrastructure.
In the aviation field, for any aircraft with a modern IRS/FMCS system, baro-VNav eliminates the need for WAAS --- the update is about the same as updating an older GPS system to a WAAS capable system.
In summary, the part of the Australian GA fleet that could benefit from WAAS is quite small. - so the benefits of PVG to an ILS like minima, given Australia's overall weather record, is quite small, far smaller than when the WAAS policy decision was made.
Forget WAAS in Australia, it ain't gunna happen. If for no other reason than the fact that AsA couldn't figure out a way to charge for it!!
Tootle pip!!