Even without OCing sometimes is better to go with a model that cools a cpu down further then a stock cooler will. If you plan to run large apps or don't have a case with plenty of airflow inside board temps will climb causing the cpu temps tp rise as well.
Even though most newer model cpus are less power hungry then the older P4s and Socket A, 754 model boards the newer boards themselves now see more power going through them for SLI and Crossfire setup when used as well as the new 12v feed for the newer designed cpus themselves.
For the usual email checking, web browsing, and lower amount of running time say 4-5hrs. a day or night the stock HSF will handle the normal operating temps there.