I had a 2400+ that always ran fairly hot. I could get it up to 60 degrees celsius under load. I upgrade to a 3200+ and now my max temperature is like 55 under load. A lot of factors can influence this though. Different cpus have different temperatures. The ambient room temperature is fairly important. The room where my computer in tends to be hotter than the rest of my house so that can always raise the temperature a few degrees.

Also case cooling and cpu cooling are important. As well as what kind of thermal grease/tape you are using to connect the cpu and a heatsink/fan.