rundymc - my opinion is that we dont need accurate readings for nb's - they dont maker enough heat. Infact we dont even have accurate readings for our cpus, yes it would be nice, but its not needed.
If the waterblock has a low thermal resistance (c/w) and also is capable of removing a high wattage like the cpu makes, then the secondry heat paths (back of nb chip) will get less heat and touching the back becomes accurate
With nb's a guess accurate to +-12c is good enough imo. 12c wont make that much difference ot overclocks and performance.