BlackBerry 10.2 OS has leaked for the BlackBerry Z10 coming in at version 10.2.0.228. Please be aware this is an alpha (early) build. Kris also notes you will need to install the BlackBerry App World from a 10.1 file.
Download OS 10.2.0.228:
This works on everything but the STL100-1. Download BlackBerry App World here.
Download at your own risk, if you do choose to install let us know how it is running on your BlackBerry Z10.