Good debate and thanks Jaba and others for your constructive input.
Whilst "Just Culture" is a key element of any SMS there are also other important elements such as SMS being built into the organisation's everyday business operations.
The biggest hurdle that I see (and this is the reason why i created this thread) is that a large majority of people in General Aviation are reluctant for any change - especially if they have been in the business for years and haven't been involved in an accident. In retrospect I believe it would be fair to say that just about everyone involved in aviation do actually have a form of SMS in place and have done for years without even realising it. Examples such as defect reporting, pre-flight planning, fuel usage management and flight following are just a few elements of an aviation SMS that I'm sure most small GA organisations are complying with on a daily basis.
One of the main issues in my opinion that is causing grief for people is that the terminology being applied to the new regulations can be a little confusing to understand. The reason behind the terminology changes are due to CASA trying to align the new legislation with the ICAO requirements. A classic example of this is the term "Operations Manual" has now been changed (in most situations) to now being called an "Exposition".