The PAYG tables and various rebates mean it is usually worth your while filling one out as just a touch more tax is withheld from wages than is due to the ATO. Means usually a slight refund if you lodge (more with deductions of course).
Labor suggested a standard deduction while in power, about $300 or $500 if I recall correctly. Not a bad idea for the vast majority of salary and wage earners who have fairly simple affairs. However, it got dumped once they started chasing the ultimately unobtainable surplus.
