The rules are in the NOTAM quoted earlier in this thread, and are the rules that I and every other pilot I know thought already applied for over a decade.
The rules as I understood them (and other pilots I have spoken to, but I haven't asked every pilot I know) were that at an airfield you used the specific frequency if one had been specified, and 126.7 if no specific frequency had been assigned.
Away from airfields, you monitored but did not broadcast on area (except for some specific high traffic areas e.g. Melbourne coastal route where broadcasts were recommended).
This sounds like it is heading back towards a requirement for VFR aircraft in general to broadcast on area. Otherwise I'm not sure what is special about an unmarked strip that requires a broadcast, as opposed to leaving an airfield where there is a CTAF defined.