Vans,
You have to be careful when relying on Dick Smith as the basis for your rhetoric when you state
despite the rest of the western world having already mandated this (according to Dick)?
As I posted
here the ICAO requirement is for TCAS II in 19+ pax or MTOW 5700kgs + aircraft.
The US requirement is for >15,000kgs turbine powered aircraft to have Mode S and TCAS II (Ver 7). In the US 10-30 pax capacity aircraft require only TCAS I (i.e No Resolution Advisories).
The difference is subtle but it is there.