Can't speak for the rest of Australia, but the Sudanese in our neck of the woods seem to be pretty good people. They certainly fill the job vacuum that the local dole bludgers are unwilling to apply for, mostly at the abattoir. There are 4 Sudanese kids in the U/14 footy team that I coach and I would have to say that they are up there with the politest, hardest working kids on the team.
My wife works at the local hospital and has has x-rayed a few of these kids (and their parents), she asked the radiologist why their bones came up a funny shade of grey and he had to consult the text books to work out that it was rickets brought about by severe childhood malnutrition, they hadn't seen it before.
So just saying that while the pay per stay scheme outlined above may not be the best idea that there are good, hardworking people with a genuine reason to leave their country that can contribute to Australia as a whole (here at least). I'd happily exchange the 'Aussie' serial dole bludgers in town for more Sudanese.
A better program might be to send the 'long term unemployed' to Sudan for a bit, see how choosy they are about jobs then.
Call me a bleeding heart soft c@#k or whatever but I have no problem whatsoever with immigrants who are prepared to work hard and contribute to the local community.