I just put together a 3570K with a Hyper Evo 212 this weekend, and I'm getting 4.4 GHz at under 50C while doing burn testing. You really should be fine with air cooling.
To bolster this further, a burn-in test (I'm assuming you used Prime95) is an unrealistic representation of load. i.e., your processor won't ever be under that much load for extended periods of time. If all you're doing half the time is web browsing or an equally light task, your processor is idling at least 90% of the time.
Agreed. I'll admit, it was a short burn-in test (yes, with Prime95). But while gaming, I haven't gotten above about 48C. And that has been some extended "tests"... >.>