Comment 25 for bug 441638

Ladies and gentlemen here comes the solution:

I realized by connecting to the machine via ssh that actually everything is running, ie. GDM, X, Pulse, whatever you just don't get to see anything which is due to a completely out of range resolution of horizontal 268kHz, vertical 281Hz.
I have now completely emptied /etc/X11/xorg.conf and voila, it works!

just as if nothing happened, all TTYs are back online, graphics are just fine, no "init: gdm main process ended, respawning"
error messages anymore!

Your's, firebug