You can probably expect it to be weeks, if not months behind other countries, particularly if you have an unlocked Z. I'm on an unlocked C6603, and it's still on the 10.1.A.1.434 build (checked for updates through PCC and SUS).
So it's now 3 builds and months away from the current release, and no indication that anything will be reaching it soon.
A real shame, but it seems to be par for the course with Sony; great devices but a terrible approach to handling updates even on SIM-free and unlocked handsets. Ironic, as the reason I shelled out the extra for SIM-free was to have a better shot at getting updates.
Still, what can you do... I suspect if we (UK unlocked) customers get the usual silent treatment for another month or so, I'll end up either selling my XZ, or rooting and installing CyanogenMod or something like that. Another possibility to consider is using flashtool and installing one of the other updated ROMs from another country, or changing your build.prop to mimic another carrier.
Either way, I'd never buy a Sony device again. I know it's "just" an update and the phone still works as it did when I got it, but frankly Sony are going to have to significantly up their game if they expect to reclaim any kind of market leadership. It's a different environment now, people expect updates and good after-sales support / customer care. If you've owned HTC, Samsung and Apple kit before, your expectations have been raised and Sony (at least in the UK) just isn't cutting it.
