I went off and played with Fedora 17 for a few days. While I was there, I noticed lm-sensors provided a complete reading of all my hardware: fans, chips, etc.
Back on Ubuntu now and lm-sensor continues to do what it has always done: produce a 4-line display.
Is it down to a version difference? Do I need to create a config file for sensors to read? (I didn't create a config file on Fedora. I ran sensors-detect, enabled it as a service, and turned on the service.)