As much as this opens up a whole world of convenience for the majority, the AFFer in me would still probably fly to say, Paris, as follows (for the increased status credits and F lounge):
BNE-MEL-DXB-LHR on QF (would most likely earn 15SCs+45SCs+30SCs - 90SCs)
LHR-CDG on BA (booked in Y but doing a cheap upgrade to I for the J SCs) - 40SCs
CDG-LHR on BA (same as above - 40SCs)
LHR-DXB-MEL-BNE (same as above, ensuring to change flight numbers in DXB) - 90SCs.
Total: 260SCs
No doubt the booking engine will soon default to BNE-DXB-CDG-DXB-BNE, which will net only 45SCs+30SCs in each direction (150SCs total return - provided that SCs can be earned on this route on EK). While I can certainly see how having Europe (excl. LHR) available as a one-stop destination may be attractive to many, living in BNE means that the only way to achieve this is to avoid QF metal completely. As a QF WP, I'm particularly loyal to QF, so if they have one of their own aircraft flying to the same part of the world that I'm headed to, I really don't mind an additional transit or two if it means being able to travel on QF metal. Nothing particularly against EK metal flights (and I'm not saying that I would never fly with them if they were associated with QFF), but I didn't invest so much time and money into my QF flying to suddenly switch all my long-hauls to EK. Either way, QF still wins as they are attracting those who favour one-stop flights, they will have a new huge airline as part of QFF, and they will still earn business from those like myself who simply prefer QF flights, and are willing to fly the long way.
I was also planning a trip in April that would have been comprised of a minimum of 3 bookings (as I wanted to visit HKG, DXB and LHR, while still earning QF points and SCs):
QF BNE-SYD-HKG-SYD-BNE
CX HKG-DXB-HKG
BA DXB-LHR-HKG
Perhaps this could soon be consolidated on a single QF booking as BNE-SYD-HKG-DXB-LHR-DXB-SYD-BNE, with the HKG-DXB leg operated by EK on a QF codeshare (as QF don't seem interested in ticketing CX on this route). This could potentially save $1-2k, so I'm not complaining if that's the case!