Australia has already had the ability to re-download any of your music, apps, books or TV show spurchased on any of your Apple devices but movies were limited to just the United States. It seems that Apple has now reached agreements with the studios internationally.
iTunes in the cloud let's you purchase content on one device or PC and then have access to re-download it from any of your other devices associated with your Apple ID.
This also is fantastic news for your Apple TV has you can now browse through Apple's thousands of movies and either rent the movie or if you love it buy it. It will then be avaialble on all your Apple TV's and other devices.