Lyric discussion by Auliya 

Cover art for Brand New Day lyrics by Dr. Horrible's Sing Along Blog

Please, can someone explain to me the reference to Australia?

I think Dr. Horrible's just saying that when he finally takes over the world, he'll make Penny his queen and give her a whole new country to reign, and I guess they just needed something to rhyme with "failure" lol

The reference to Australia is actually because Australia is a country populated by the descendants of convicts - it was a penal colony after all - and aboriginals. Their nation hero is a criminal and it's perfect for building secret labs. Lex Luthor in Superman 2 asked for Australia. The horrible doctor's just giving a shout out to this and promising Penny her own country.

-you're welcome