I haven't ran into many problems on my PS3 overheating, but some people who play on their PS4 8 hours a day may like this new feature. It seems like the PS4 has gotten a huge upgrade on their fans I believe, the PS4 will run a lot cooler than the PS3. They lowered the temps by a significant amount, and I'm sure some of you will like this change.
Via Nowgamer
What is interesting is the tidbits of info the FCC registration coughs up. According to the registration, the PS4 will run at 5-35 degrees Celsius - which is fairly cool compared to the PS3's average of 45-55 (over 60 and you're at risk of the YLOD).
Via Nowgamer