Our good friend @Jaysus858 sent us the below screenshot showing OS 10.1.0.4181 being pushed out to O2 UK BlackBerry Z10 users. As you can see in the screenshot the OS is 178MB is size and at this time there is no word on what has changed. Changes most likely include overall enhancements and bug fixes. The OS is said to be available via BlackBerry Link as well as OTA. You can check for the update by going into Settings> Software Updates>Then Check for updates.
Let us know what you think about this update in the comments!