"Their Source? Apple resellers who were apparantly told this ahead of schedule (perhaps slightly unlikely)."
It's not that unlikely really, if it is indeed not locked to a carrier then the only way they can really sell it at all on the ground (as opposed to online) is through the resellers, which have a large presence in Australia. Giving your only way of selling the Phone a heads up is hardly surprising. The MacTalk guys also have pretty strong ties to the resellers as well, some of them working at them (or used too).