During last year's election campaign, ALP leader Kevin Rudd promised to overhaul Australia's Freedom of Information Act to bring about greater transparency. Unfortunately, those plans seem to have hit some snags, and will be delayed for public discussion. But they will be doing one thing immediately: ending the ability of Ministers and senior civil servants to issue "conclusive certificates" that release of information is "not in the public interest". It's a small victory, but a significant one, which may help to end the culture of unaccountable secrecy in Australian government circles.
OTOH, it's clear that in Australia, it is culture which is the problem. The New Zealand government has an equivalent power to veto release of information by order-in-Council (in s32 and s32A of the OIA); the difference is that they don't use it (I think the last such use was in the 80's). Instead, we have a culture of relative openness and acceptance of the Ombudsman's review. And I think its primarily that, rather than the law, which really needs to change in Australia.
