I have a Dell XPS M1710 laptop which I use for mobile video editing. I have to run out files which keep the CPU running at 80% to 100% speed for an hour or more sometimes. My heat monitoring programs tell me the CPU is getting up to 75 degrees Celsius sometimes, whereas previous it would run solidly at about 45 degrees.
That's normal... Mobile Core2Duo and CoreDuo have a operation threshold of 100 degrees celcius. Throttling won't even kick in until you start hitting 95 degrees.
Just look at the intel tech specs if you don't believe me.