curl -O http://download.virtualbox.org/virtualbox/5.2.2/VirtualBox-5.2.2-119230-Linux_amd64.run
Lots of things works, lots of things complained about symbolic links already existing (step 1 of this script attempted to remove my Slackbuild VirtualBox with, I'd say, partial success), and then it ended on "unable to start kernel drivers". Not a good sign I thought. Just for luck, another reboot. And then, I re-ran "rc.vboxdrv start" AND IT WORKED! So now I'm running 5.2.2!!
So, I fire up an ALL NEW Oracle VirtualBox with lotsa Oracle branding (hmmm... didn't remember all of that). I attempt to start my Windoze VM - no go. It complains about USB 2.0 support not being there and suggests I try installing extensions.
Implementation of the USB 2.0 controller not found!
Because the USB 2.0 controller state is part of the saved VM state, the VM cannot be started. To fix this problem, either install the 'Oracle VM VirtualBox Extension Pack' or disable USB 2.0 support in the VM settings
I re-run extensions. Still no go. So, I retro my VM's USB support from 2.0 to 1.1 (trying to think how often I use USB with a VM anyways?) AND IT WORKED!
Ok, not the slickest solution in the world. The installer did something with Python bindings, from what I could tell, installed some things, fixed some things, possibly broke my USB 2.0 support but otherwise bailed me out.
So, if you're desperate - you're welcome.