its not really a protest vote... its more like a vote for labor
I don't get why people say that. In the House of Reps voting is preferential, if the greens don't win you could easily put the liberal party as your second preference and they'd get the vote. And for the senate, you just vote under the line. It only goes to labour if you actually want it to!
I'm not sure about the link nina posted. I know the Greens have some problems but so does every party. Realistically, we're not voting for the Greens to be government anyway, so it's all moot. Furthermore, they probably look a bit rough around the edges because I assume that they can't afford as many advisers as the two major parties.
Anyway:
Greens: 43%
Labor: 29%
Donkey: 17%
Coalition: 9%