Hi adenda,
<<I thought under the new scheme a SYD-MEL(stopover)-WLG(stopover)-SYD itinerary would have each sector tallied as if a return flight - on the basis that there are no O/W awards anymore. >>
No - it is worked out as one trip (unlike some other airlines) - (only if you want to).
<<Am I to understand that a multi-sector itinerary is still calculated by adding the individual one-way sector mileages and then adding 10,000 points per stopover (excluding ultimate destination)?>>
Correct. So SYD-MEL-WLG-SYD works out to be 3428 miles or 5524 kms round trip - this puts it in zone 2 (30,000 points in economy). You get one destination free (MEL or WLG) or you could fly the route without any stopover penalty if it meant getting a better connection through MEL - without a stopover in MEL. If you want to break your journey in MEL (I think it is by more than 8 hrs) then the stopover fee applies. So you can do SYD-MEL (4 day stopover) MEL-WLG (7 day stopover) WLG-SYD for 40,000 points in economy. I am sure you can work out many more combos...
Cheers... Bruce