Oh, and it's still there.
Look at the webcam:
http://www.aal.com.au/media/webcam.aspx
No tankers in sight.
Maybe Jetstar needed to park a plane for a night?
Maybe it's some kind of special charter?
The mystery deepens!
No more Qantas/Jetstar planes are due to leave ADL tonight bar QF53 (off to AKL @ 22:25). You can see that plane in the background of the webcam picture.