Simple but effective. An updating list of Australian book releases. Discoverability still hasn't been solved, so this is a small step to help. The site isn't automated, so there's no guarantee that everything is updated but:
If you are an author or publisher whose book(s) does not appear here, please contact us by email on australianbookreleases [at] gmail [dot] com.
Check it out here: http://australianbookreleases.com/