A topic close to my heart on so many levels...
Firstly given the long history of competition law worldwide, going back to the oil rush and Sherman act in the US and - very broadly - similar provisions in Europe nationally, prior to the eu taking control of a large amount of European competition law generally, I find it surprising that Australia don't appear to have, from those articles you posted, the case law or regulatory body to deal with it.
More surprising to me still that If relying on market forces to keep competition healthy, an approach that has failed historically elsewhere, why some other multi national retailers haven't spotted a gap in the Australian market and moved in. That is perhaps another argument however.
Is there no regulatory body in aus to deal with this? SUrely if price wars are occurring there is a real chance of price fixing between the two also?
On the other hand I love beer, so why not?