It (RNP approaches)doesn't really seem to be catching on.
There are now RNP-AR approaches for BNE, CB, ML, CNS (I thinK). They're catching on in a huge way. RNAV approaches into CTAFs and procedural control aerodromes are the norm for QF 737s.
QF 767s can do RNP-AR into BNE. Small issues with the design (both procedural and FMC programming) of RNP-AR into CB and MEL but they should be up and running for the 767 within 6 months.
This is on top of the RNAV approaches that QF GE powered 767s CAN do in virtually every major aerodromes around Australia.
There is no reason why any 777 or 744 operator can't go through the appropriate motions and avail themselves of the RNAV straight in to 34 at MEL.