Many of the world's poorest countries struggle to increase their standard of living by exporting their goods to the richer nations of Western Europe and North America. However, they often find their entry into these markets blocked by tariffs and other protectionist measures (such as quotas), politically popular but economically unsound. Australia has decided that it will back up its rhetoric with action, as imports from the 50 poorest countries (as well as East Timor, which has not been added to the UN list as of yet) will all be quota and tariff free. It would be nice to see the US and the EU follow suit; the politically powerful textile and farmer's groups will be displeased by the action, but both the consumers of the nation and the poor countries that produce the merchandise will benefit.
A link to the press release from the Prime Minister's Office can be found here.