I'd like to generalize the question a bit--is there even an upgrade mechanism planned for this? With a plugin, presumably it's just a matter of updating the PBI, but VirtualBox isn't a plugin, it's a separate jail template. How would that be upgraded?
I had set up a VBox 4.3.10 jail under 9.2.1.6-RC. When -RELEASE came out, the template was up to 4.3.12, but I didn't see any way to upgrade, so I exported my VMs, set up a new jail, and imported them into the new jail. Was there a simpler way to do this?