So... let's see what are we missing there... oh, I know, NVIDIA drivers...
WARNING: backup /etc/X11/xorg.conf NOW!!! Then read on.
Updated NVIDIA driver, left out of the X server for a few hours while trying fixes which didnt work. Finally used a combination of drivers, new drivers, force installs, updates, manual edits and crap like that to make it re-start.
Below is a picture of a failed DX surface initialisation.
Click to enlarge