The most alarming issue is that some people who sent it in for repairs under the stock warranty program had the same issue just months, and even days, after receiving their supposedly "repaired PS4". It appears to be an issue with the Power Supply Units (PSU) that Sony is putting in their PS4s.
So what happens if you send it in for repair under warranty and then it happens again? Well, after the repair you have 90 days of extended warranty. If it crumbles on you once again after that time period, you are on your own and would have to pay a nice chunk of money to get it fixed - or you could buy an Xbox One (eeeeewwwwl!).
I am sending my PS4 in for repair at some point today and was told it would take 7-10 business days to turn around from the moment they receive it. As my subsequent 90 days of warranty begin to come to a close I plan to purchase a $59.99 plan of extended warranty for 3 years. As I see this having to be a routine thing of sending in my PS4 for repairs every couple of months. You can buy the Sony warranty directly from here or by logging into your Playstation account online and looking under Playstation Protection Plan in the Knowledge Center.