Well (even thought its a bit late) Happy Birthday, Matt
I am not sure what caused my issue on my older desktop of everything installing and booting fine, but after a reboot, xserver would fail to start (Could likely be a hardware issue, the only effects me due to the hardware in that PC). I tried to (granted I am going off the manjaro wiki and I'd be lost without it) disable and re-enable mdm, though it keeps doing the same thing. I then (just picking one at random, honestly.. my favorite is mdm) disabled mdm and installed/enabled lxdm and the (crossing my fingers) problem is gone now. I am not sure what happened, since I installed a few packages via yaourt and rebooted a few times and there was no problem. It was after the latest round of updates that coughed my mdm up, and to be honest, it MAY have done the same thing on that PC if it was stock Manjaro.
Anyway, i am off to setup (for the first time NOT in a virtualbox) Arch, which I have been meaning to do (learning Arch) for some time.
Hope that your fix really did fix the issue with Virtualbox (for your sake, lol). I cant beleive one of my new favorite distros, got better with this respin... but it did.
As I said before, thank you and Spatry for all the time, effort and hard work you two do.