This might be moving slightly away from the topic of the thread, however...
I've recently started working in a multi nationality environment, and spent the last two months trying to understand both the US and UK systems, having worked solely in OZ. What I've found is that the US is vastly different in the very principle of how they operate, compared to how we do. My observation is that oz is high regulated (for good reason), which is not to say that the US isn't, but in a different way. I find that I'm now working in conditions with greater freedom (which I have to say I don't particularly like overall, but like other aspects of it) some of which has come about from the US way of doing things (yes, this is a bit of a generalisation, please take it in context), ie. tower can release aircraft into approach airspace by which ever means they choose, no coordination required. To move to an airspace design system similar to the US, would also require a significant cultural shift on behalf of the oz avaition community in order to be successful and this issue does not seem to have been addressed in any of the changes.
A comment was made previously about VFR. Whether we agree or disagree, the mandate of the ATSB is to priortise fare paying passengers and matters of public interest, which in turn means that change is likely to come about for the IFR community and the manner they fly before it does the VFR community as a result of the investigations carried out. Incidents not investigated are recorded in the incident reporting system, which is managed by CASA - and so relies largely on trend spotting and data analysis to identify areas for change.