Comment 1 for bug 1265570

It left me in the dark too (booting to text mode console) and i lost 3 hours looking for the problem.
At first my solution was to manually load the nvidia-331 module with modprobe and then I found this bug report sating that bumblebee blacklists the nvidia drivers.

Uninstalling (apt-get remove) doesn't remove /etc/modprobe.d/bumblebee.conf but purging does (apt-get remove --purge).

Now I'm wondering what will happen to not so tech savy users...
In systems without dual graphics it prevents X from loading at all and even using ppa-purge to remove xorg-edgers packages does nothing (it was my first try) as /etc/modprobe.d/bumblebee.conf is still left behind.