I haven’t followed it all that closely but with Rudd/Labor crashing at the polls and the Greens rising, doesn’t this make a Red/Green coalition more likely? Or something similar to the new UK situation? Or (hopefully) can the Liberals/Nats pull it out?
A government in Australia is formed by the party (or parties in Coalition) with the most seats in the House of Representatives - similar to what happens in the UK with the House of Commons.
The Greens have never won a seat in the House of Representatives, and the best they are hoping for in the coming election is that they might win one for the first time.
If we wound up with a Parliament that was evenly split between Labor, and the Liberal/National coalition, a sole Green MP might enter into an agreement with Labor, but that's the only situation in which it could happen at the moment.
The Greens do have a significant presence in the Senate, and their current polling would suggest they might get a couple more Senators, which might give them the balance of power there, which would make things awkward for whoever is in government, but would not actually change the government.
On current polls, the Liberal/National coalition would win the election. Whether that will still be true at the time of the election is hard to say. If Rudd loses, it will be the first time since 1930, Australia has thrown out a government after only one term - it's unusual.