That's only 67C, so on the warm side of normal, but Apple does tinker with fan settings to try and keep the noise level down. That's also a perfectly normal temp to have if there's something keeping the CPU busy.
I have an IMAC , Snow Leopard, 2.66GHz Intel Core 2 duo, 10.6.3 with a CPU registering a temp of 153??? CPU fan running at 1200 rpm. Why the increase in temperature?