Those temps seem fine. I hear that you don't want to be much higher than 70c. I cant say I looked into that a whole lot, but it sounds right to me. Keep in mind that the computer will do at least SOME to protect itself from melting down.
Just to brag a little, here is a pic of my temps after running the slightly overclocked (3.4 clocked to 3.8) CPU at 100% for about 5 hours.
I was pretty happy with that since the temps move up or down 1 degree for pretty much the entire run. Also my fans which are controlled by the CPU fan port on the motherboard never even throttled up at all. Nice and quiet
Sean