Sony has announced that the PS4 has received an optional firmware 5.01 update, and as you may have guessed, the patch notes aren't too specific.
To get the update all you need to do is go into Settings on your console, and then select System Software Update. After that, click Next and then Update, and you'll be on your way. Alternatively, you may also use a computer and USB storage device.
The update "improves system performance", so as with many of the updates chances are you might not notice any difference. Have you noticed any difference though?