What are our chances, if conflict were to begin?

One of the biggest current news items here in Australia at the moment is the approach of four Russian naval ships, including the formidable Varyag, to coincide with the G20 talks in Brisbane.

I don’t understand naval warfare that well, so how would a potential battle unfold if it were to occur? Although the Russian ships seem to out-gun ours by a significant margin, they are also likely within striking distance of our F/A 18s, and they are a long way from any form of re-supply. What would it take to defeat these ships? What would we be likely to lose in the process?

Please note this is purely hypothetical. I really don’t expect any trouble, and would be horrified to see any escalation to actual combat.