EDIT: To expand on where I'm coming from, I'm the technical lead at a web agency in Melbourne so I make recommendations on what hosting providers we use, both for our staging servers and live servers for our customers' sites.
We already have a few staging and live servers with AWS in California, but for most live servers we have to use Australian hosting providers for lower latency and (sometimes) for legal reasons regarding storage of customer data. I guarantee that if AWS were to open a facility in Australia, all of our hosting would move to that facility ASAP.