That’s the real benefit of visiting NPU (pun intended), you often know what happens in future. So, we found and reported a release candidate Windows Phone 8.1 build 8.10.14219 1-2 days back and it is the Build that is rolling out to developers preview devices today.
Yes, we checked and it is live now for all my Lumia devices enrolled to dev preview.
Using the scheduler feature of software updater, that landed with last preview build, once you have downloaded the 8.10.14219, you can decide whether you want it to automatically install at your preferred time or just tap to install now.
The whole update process took around 20-25 minutes including migration of the data back to the phone and getting up and running.
We are now checking your updated devices for changes and wait for our changelog to know what the latest Build brings other than Cortana for France, Italy, Germany & Spain.