Sony has released a new system update (version 1.52) for the PlayStation 4. For those who have already enabled auto downloads and left the PS4 in standby mode, the update should have automatically downloaded and will install the next time you boot up your console.
Official patch notes have yet to be posted to the website, but Sony's PlayStation Twitter has confirmed that the update "improves system software stability." We'll be sure to update this once the official patch notes are up.
On November 20, Sony released update 1.51 which contained some minor changes including improved stability of system software and "minor refinements" to elements of the system UI.