Just went onto the PB website and can book flights - $299 there, slightly less back.
Looks like 2x weekly (Tue/Sat) from mid November, ops by Virgin Blue. Also looks like the aircraft stays almost 24hrs in HKT before returning home (return on Wed/Sun) - minimise crew cost and maybe costs less to park an otherwise unutilised plane in HKT than in oz?
Both are daylight flights which will be popular with the punters and well suited to hotel check-in/out times.