What you read is wrong at least the context. "New" mining investment is coming to a end at least for the time being, benefits from mining are set to continue for decades. There are however other threats to the Aus economy such as the ongoing currency war and the housing bubble.
As I just posted in another thread, the devaluing £ and $US is mostly because of money printing by the US and UK. A slightly stronger or weaker Aus economy has little to do with the exchange rate, Traditional economics no longer apply. Even if the RBA lowers the rate to 0 it would only have a temporary limited effect as seen with recent rate cuts. If Aus starts also printing money to counter, the story will be different.
The UK has printed over £300 in the last 3 years!!, that is buying growth at the expense of devaluing the £. The UK can't keep printing money forever, don't think I need to come up with examples of why that's a bad idea.
I suggest transfer soon, the US is about to do "QE3" and the UK has already printed this year, seems to be the current policy with no sign of a change.