It's worth noting however, that the devices are actually running stock Android, instead of the Sony-skinned ROM we’re expecting to land next year.
This is because Google released the source code for Lollipop earlier this week as part of its Android Open Source Project.
The newly available code has allowed Sony to ready up a stock version of Android based on the AOSP, and get it running on the trio of Z-series devices.
Sony says it’s not ready to release publicly just yet, but promised to push out the files as soon as possible.
Fredrik Ekstrand, Sony’s Head of Software Portfolio Planning, said: “We know there’s probably a few of you itching to get AOSP 5.0 running on unlocked Xperia devices.”
“We’re working to provide updated versions of the necessary binary files as soon as we can.”
If you’re keen to upgrade to Lollipop on your Z3, it’s worth mentioning that stock Android is an assuredly different experience than Sony’s current OS.
For starters, it doesn’t actually come with what you’d expect to be standard apps, for instance the Play store.
It also skips out on all of Sony’s added bloatware, of course, and shows off the Google’s new material design aesthetic.
A word of warning however - rooting your Xperia device means you'll lose DRM keys for some of Sony's built-in software, meaning camera quality will degrade permanently.
If you’d much rather have a Sony-officiated ROM, you’ll have to wait until early 2015 when the Japanese firm rolls out its own version of Lollipop across the Xperia Z series.
In the meantime, check out Sony's AOSP ROM video:
Read More: Sony Xperia Z4 release date