Confirmed, TMPIN1 is socket temperature.
TMPIN2 seems to be VRMs, reached 80c in no time with CPU under load. (Phenom II in this machine)
However the socket temperature reads between 5 and 10c low. My 965 hit 68c load on cores, and the max reached for TMPIN1 was 63c.
This CPU is on the stock cooler, which is the reason for high temps.