bing - Tj is supposed to be the junction point between the die and the PCB. Is there any textual explanation that comes with this picture to clear this up, as it is not clear from this picture.

kwalker - C2D desktop processors are also designed to have a 85C Tjunction temperature. The post you quoted in here states that there is no such information in the MSRs. This sounds a bit odd since it is basically the same architecture, so it only makes sense that there is a Tjmax value. In addition, Quad cores have a Tjmax of 100C, which also leads me to believe this value does exist.

In addition, Intel has implemented a DTS in each core on the C2D/Q desktop processors. This DTS is only handy when used with the Tjmax value(the reading in TAT/Core temp is actually -> Tjmax-DTS=CoreTemp).

Regarding bios/speedfan/other software readings, they are derived from the thermal diode. You should really prefer TAT/CoreTemp readings instead of the diode reading. While the DTS have an A/D convertor on die, the thermal diode sends an analog electrical signal to the sensor in the motherboard. This can lead to mistakes in the temp reading.