The root is courtesy of XDA’s DooMLorD who has in the past been pretty instrumental when it comes to various mods and tweaks related to Sony’s Xperia handsets. The Touch Recovery is said to be based on ClockwokMod version 6.0.4.6 and will require users to unlock the bootloaders of their phones.
We can only assume that unlocking the bootloader of the Xperia Z2 should not pose to be too much of a problem. Sony in the past has been pretty friendly with developers and has even provided instructions back then on how to unlock bootloaders of their phones, so we can only assume the same will be applied with the Xperia Z2, if not probably someone from the community will figure it out.
With an unlocked bootloader and the ability to gain root access, Xperia Z2 owners will be able to flash all sorts of custom ROMs onto their phone, like CyanogenMod, for example. The root access will also grant users the ability to install various tweaks and mods that might not be allowed prior to rooting, so if you were thinking about getting the Xperia Z2, hit up the XDA Developers forum for the download links and the instructions.