Thanks. Turns out I'm running gdm. I recall when I first upgraded to 12.04 LTS, I had the same situation.
Steam doesn't like the 304.48 nvidia driver. I need to figure out how to update it, and the gl packages. I would have thought it would have been done through the software/update manager. -- Is a person a failure for doing nothing? Or is he a failure for trying, and not succeeding at what he is attempting to do? What did you fail at today?.
In 12.04 I was able to get the latest nvidia drivers through Jockey by installing the "NVIDIA accelerated graphics driver (**experimental**beta) (version experimental-310)" drivers.