OK, I'll walk back some of my frustration with QF as it turns out they handled the cancellation very well after all.
I received a callback from the QF call centre about 40 minutes after my initial call. By that time QF had rebooked me onto a direct flight with VA that gets me to Brisbane within 20 minutes of my original QF flight, even keeping me in Business. I certainly can't fault that side of things, and it's completely above and beyond for QF to rebook me onto a different carrier in J.
The QF call centre inbound experience is still a sore point though. I needed to get the VA booking reference so I could use their online checkin, and as a joe-nobody (I didn't even enter a membership number) my call to Virgin's call centre was answered within 15 seconds and I had the reference number 2 minutes later.
All in all I'm feeling a fair bit happier with QF than I was 90 minutes ago, so credit where credit is due.