It's me again with yet another insane idea.
First of all : rge, you rock!
Now back to the idea. As we know Intel might mean different things with their new Target TJ value. It seems obvious that those 70C & 80C for 65nm mean something different than 95-100C for 45nm despite being given the same name. But, as rge has proved, at DTS=0 we are supposed to get IHS temps very close or equal to those listed in thermal specification (72-74C for 45nm CPUs). But personally I cannot believe in a gradient of 27C (or maybe even more, as it will most likely increase with higher temps) between core temps and IHS. The previous P4 testing is a good proof to that. On a 65nm CPU this gradient would've been much lesser and much more reasonable, should we decide to use Intel's TJ Target value of 70C for B2 or 80C for G0 (15-20C offset from guessed TJmax used earlier) and IHS values taken from processorfinder of 60.1C and 72C respectively. So maybe these new "official" numbers for 65nm aren't that wrong? Thermal specification for 45nm is very close to that of 65nm G0 stepping (72-74 vs 72). If we (hypothetically) assume TJmax=80C (same 20C offset) for 45nm CPUs then we'd see only 7C gradient in rge's testing and 6-8C gradient at DTS=0 according to Intel's specs (72-74 IHS temps and this hypothetical 80C Tjmax). The abnormally low core temperatures in this case at idle & medium load could be explained by sensors' inaccuracy (slope error) while high load core temps would be more accurate & close to IHS temps.

Sorry for my English, I'm not sure I expressed everything the way I meant to.