Gibbo,
I sincerily beleive that the ideal platform to conduct air attack and incendary is via lights such as the 206 , ec 120's etc, they do not require a huge load carrying capability as it is often yourself , air attack supivisor and maybe a DFO so 3 at max but usually only 2 persons on board during recon, AA, mapping etc.
The lights are cost effective and well suited for the job, im quite happy lurking around up there in our 206, sure id like to do some bucketing but thats life, the boys in the 600+ litre capability are doing fine. Recently on a fire in late september this year in the hunter valley area, i was doing air attack for a 407, and a 206L4 bucketing and things went just fine.
Its not a case of the RFS getting rid of the lights, just a matter of better alocating resourses i think.