I own a Q6600 OC'd to 3.2Ghz, I can tell you that I do 3D rendering and animation work and push the CPU to maximum load almost 24/7. under heavy load i get about 72C degree and this machine has been running 24/7 for almost 2 years without problem. So I'd say, yes 72C is a little hot for my liking, but its not going to cause any short-term issues, besides, Q6600 is on its way out, my suggestion would be to OC the living shiz out of it till it dies, then upgrade. =)
Whay VCore voltage do you use for 3.2 Ghz?