Well the RAN is getting at least 3 AWD. While not as capable as a burke, they are *WAY* more capable than anything we have ever had.
We do have Phalanx but not on everything. I wouldn't be suprised if we got more of them.
The reason why the politicians didn't get them, is because the logic is, if we ever needed it, the americans will be with us to supply it. Ie not hot situation without the americans and their might by our side. US air defence will protect us wherever we go. USA all the way. Middle of the cold war and all that.
However, East Timor proved that wasn't the case. We will get US support, maybe, on US terms, and at a time that is convenient to the US. The US support may put screening requirements that are above our capability level, meaning our entire navy will be preoccupied working with the americans to provide what they need we won't have a navy able to perform the mission. It was now even for seeable that we may not get any useful US support, even if they wanted to give it to us (internal, external, operational or global strategic issues).
We have to have our own independant expeditionary capability if we want any say in what happens in our region. IF PNG (or indonesia, or a province, or Fiji, or Samoa, etc) collapses, you could be looking at 100,000's of refugees per year, but neither china nor the US will be keen to commit to a mission that is very far for both of them, with most likely no "winning" strategy possible. However other regional powers may take opportunity to redraw boundaries or add to it outside of their control (rouge military or police units) etc.
The LHDs however, I think will be relatively well protected and will always be escorted. They will most likely have Phalanx and eventually ESSM. However, the escorts need upgrades. We need that 4th AWD, and we need the new frigates to be far more capable than what we have. I also believe we need PAC-3 and SM-3.
With only 2 LHD and 3 AWD's, Choules does have the potential to be right in the middle of a sticky situation.