where are you gonne use it? No one will accept Aussie dollars because they can't deposit into bank directly without paying foreign currency handling fee. beside, bank exchange rate won't be better than outside exchange rate too.
Even if its 1:1 now you wont get that at money changers, they need to charge a spread to cover their risks and costs. You would likely have to pay slightly above S$1 to get A$1 now. You would pay S$1 for A$1 only if the exchange rate strengthens a little further in S$'s favour.