I have an E6750 and my idles are about 28-31 degrees and load 28-47 depending on ambient temp........The main thing you have to consider is that if your room is hot you are gunna expect high temps for idle and load but unlike a freezing cold room which could see your temps drop. Mind you saying this it depends on multiple things ambient temp, cpu cooler, enough thermal gel applied to cpu etc
Also, do you have Intel Speed Step turned on in the BIOS? Oh, and did you manually set the voltage for your E6600 or is it on automatic. Speed Step will underclock your CPU when it is idle and the automatic voltage setting COULD POSSIBLY (I never tried this to see if that really happens) lower the voltage since the CPU was downclocked, which means your temperatures will drop.