As of today (May 4th 2011) Google shopping is now active in Australia for products, I’m just about to wade through the code in mage 1.5.* to try and extend it for Australia - has anyone already done this?
Update: One immediate problem, the Google Base API is being shut down in a couple of months. It doesn’t return valid AU product types from Google and probably never will, what’s actually needed is a rewrite of the entire Magento Google Base module to switch over to the Shopping API.
At this stage I’m not sure what direction is the best, rewrite this module to switch API’s, wait for a new Magento release to do it for me (which may take ages as the underlying Zend Framework doesn’t yet support the new Google API) or create a simpler XML feed module based on the existing RSS code. I’m open to suggestions!