I'm not so sure if NAS stages 2c and 3 will occur in the near future, despite the NPRM. NPRM's have been deferred before and can be again. Based on the available information, rollback of NAS 2b is still possibly three or more months away. The completion of the subsequent design safety case after rollback will also be a lengthy process with the levels of consultation that will be required.
Airspace reform is at a stage where nobody really understands the risks of the pre-November airspace model, or any NAS stages planned, because no-one has completed a detailed risk analysis. The idea that the NAS model in the USA was OK therefore it must be OK in Oz has now been formally discredited by recent events. We all have opinions, but we need analysis to back up the statements or planning assumptions.
A design safety case is needed to benchmark the level of risk of the pre-November 2003 airspace model. Whatever that risk level is, it should be deemed to be as low as reasonably practicable (ALARP) because it was the accepted airspace model in use for a long time. Any future airspace reform program be it NAS or something else, also needs a design safety case that also quantifies the risks. These risks can then be compared with those of the current model, and value judgements can be made by industry about whether the benefits of the reform are compatible with the levels of risk. It may be that in a future stage of airspace reform, the levels of risk do increase against the pre-November benchmark. However, they could still be deemed (by industry) to be an ALARP acceptable level of risk, if there were also benefits that justified the level of risk. But at least the decision would have be made from a base of knowledge that is currently not available. No airspace model has zero risk, so where do we start and where do we want to go?
In summary, my point is that most of industry has a viewpoint about NAS, some for and some against. All our collective opinions have been based on our experience and knowledge of the industry group we belong to.
However none of us actually know what the levels of risk are of the pre-November or current NAS airspace models - this analysis has never been carried out. We all have opinions, and recent events have confirmed that some of or opinions have turned out to be right and others to be wrong. When it comes to the determination of risk, gut feel is a good start, but it must be backed up by reasoned analysis based on all the available evidence that we collectively as an industry can offer.
We must all assist with the hazard analysis and risk determination processes for the pre-November airspace model (and any subsequent reforms down the track). In this way we can all get to understand the basis of the risk equation through appropriate analysis and then apply our collective industry knowledge to make reasoned judgements about benefits.