Android developer extraordinaire, Doomlord from the XDA-Developers forums has managed to successfully root the Sony Xperia Z before most customers have even bought theirs yet!
The fast turn around was a team effort by Doomlord modifying the code of a Nexus 4 root, while Teamviewer remotely tested the code on read-world devices. The effort managed to be a success, with other forum members offering that the root has worked for them also.
If you’re looking to pick up a Sony Xperia Z and hope to root it as soon as you get home, be sure you are fully confident with what you are doing, as their isn’t a recovery tool available just yet. You have been warned.[ Source ]