Sony just released PS4 update 6.0 to the public, and following on a grand tradition of feature-rich, whole-number updates… it "improves system performance."
That's the extent of the patch notes. If you have automatic updates enabled, you'll probably find your PS4 has installed the new, roughly 400MB update since you last checked in. But you probably won't notice much difference. Thankfully, there's good reason to believe this may just be a prelude to bigger PS4 update plans coming very soon.
Hopefully the update sitting on your PS4 hard drive now is just preparation for bigger things to come, especially with Tokyo Game Show set to begin on September 19.