As an Australian, I was really disgusted by the way people have responded to this case. I'm not saying that the death penalty is right, but I can understand why they didn't let Van Nguyen go, because think about how other death row prisoners and the families of past executed prisoners would respond. It would get really messy. That's part of the problem of having such a harsh penalty established in the first place.
Anyway, many other foreigners (probably Australians too) and locals alike have been imprisoned and executed over the years, yet there was no uproar about it or threats to boycott Singaporean based businesses before. And in a few months time, everyone is going to move on, and not care about the issue anymore. It's just the usual media-circus bullshit, like the Schapelle Corby case earler this year (she's still in prison, why have people lost interest now? Because it's no longer on the nightly news).
It also seemed like people were forgetting that he broke the law. It doesn't change anything if the mother comes on TV and makes him out like a victim, because he's not.
Also, the Bali 9 have committed the same crime, and there are rumours of entrapment by the Australian police. The general public opinion is that these guys deserved it. Granted what these guys have done was stupid, but they are seen in such a negative light.
BTW, Australia didn't "fail" anywhere, in fact John Howard and the Federal Govt. has given this a lot of attention, and they did all they could without inteferring in Singapore's politics.
EDIT: P.S. I love Singapore. I got to spend 12 hours there, and it was so easy to get to downtown from the airport and back. Plus great architecture, like that art centre that looks like that spiky fruit. I wanna go back there for a proper shopping trip some time.