The Australian Government is trying to unify its cyber-security policy by bringing cyber-security into the portfolio of the little-known National Security Resilience Policy Division, part of the Attorney-General's Department. The Australian IT article linked above paints this primarily as a response to espionage and cyber-warfare mounted by sophisticated foreign government intelligence agencies. This is an un-necessarily narrow interpretation - on the Internet small interest groups, organised crime and even individuals can mount attacks with national security implications.
One possible direction for the Attourney General's Department is mapped out in the Estonian Cyber Security Strategy document released last year. Published in the wake of crippling nation-wide infrastructure denial of service attacks, Estonia's document is a sound and well-informed broad national security policy that Australia might do well to emulate.