Update: The new update is indeed rolling out right now and weighs in at 217.2mb
Sony have just announced via Twitter that there will be another system update released later on today that will will help improve usage of some applications.
According to some PS4 owners the update has already begun rolling out in some regions, we still do not know the size of the update or have the official patch notes as of yet.
It would appear this update is more for stability than adding any new features, so do not expect to see PSN name changes in this update!
We will update you when more details emerge about this update.