CyanogenMod 10.1: A new wave of nightly builds of this customROM are now available for a number of handsets and tablets, which brings access to Android 4.2.1.
Granted, all of this could just be a customROM built to emulate the latest Google dessert, so we can't be a full hundred percent certain that it's authentic.
CustomROM fans were briefly teased with the prospect of Verizon loosening its anti-modding stance when the HTC Droid DNA first arrived: in the pre-release days, the official HTCDev portal allowed unlocking the DNA's bootloader.