when i first got my prescott( bout 2 weeks ago ) it was running 45 IDLE and about 55 during games.. because I had a williamette b4 that and was gettin CPU temps of about 29, I got a lil worried too but its all good... the heatpad on the stock p4 hsf melted in about a week lol, so I got a zalman now and re did the thermalpaste, now it runs about 38 IDLE
its hard to compare AMD with P4 but if ur worried about it , just get a better cpu heatsinkfan