YES! I finally got lm_sensors to grok my CPU temps. I upgraded to CVS lm_sensors and i2c, and had to force it to load one of the chips, because it thought it was a misdetect.
Idle temp (well, playing mods and browsing the web) is 48 for CPU0 and hovers between 48 and 49 for CPU1.
With cpuburn, I got CPU0 up to 58 and CPU1 up to 62 before i chickened out (probably 10 minutes). cpuburn scares the daylights out of me.
CPU0 had better be the one next to the exhaust fan :P
My machine is now missing only two parts: an IDE cable that doesn't puke all over UDMA100, and one of the plastic thingies that snaps the front bezel onto the case. Hopefully, I'll find the plastic thingie when I'm cleaning up.(update)
...or not. There seems to be no pattern in how the hardware monitoring chip enables itself. Maybe a BIOS update will fix this. There's a new BIOS from last week...