my new 13" mbp is also runing on the hot side, 43-60C with normal browsing running 2-3 apps, watching videos online will take it up to 70C+ and running graphical apps like google earth will take it over 80C after a while.
the fan stays at 2000rpm, I'm fine with it, rather want a "hot" laptop than a noisy one.
watcing video files ON the laptop itself wont heat it up really.. weird.