There's a theory making the rounds that the MacBook Pro's high temperatures are attributed to a misapplication of "thermal grease" that's applied to the CPU and GPU chips during the manufacturing process. A post by >/showthread.php?s=&threadid=1864582" target="_blank">Interrupting Moss on the Something Awful forums mentions that "it just takes a slight misapplication of thermal grease on a MacBook Pro to make the temperatures skyrocket."
The amazing part is that if true, Apple techs are assembling MacBook Pro's with too much thermal paste because the MBP service manual tells them to! According to MacBook Pro service manual "0.2-0.3cc" of thermal grease should be applied to all three chip mating surfaces. Interrupting Moss however, >/showthread.php?s=&threadid=1864582" target="_blank">states that reapplying thermal grease "properly" dropped the running temperature of his MBP by 14 degrees Celsius.
News source: ZDNet