We learned yesterday that Microsoft plans to begin the roll out the Windows 10 Creators Update on the 11th of April - next month's Patch Tuesday - and coincidentally the end of support date for Windows Vista.
It also appears that Build 15063, which was released to Windows Insiders in the Fast Ring on 20 March and the Slow Ring on 23 March, is the final base build for the Creators Update. In fact, yesterday Microsoft released the ISO image for this build to its Windows Insider site so that testers can download the file to perform a clean install or in-place upgrade for additional devices they want to test with this release.
Unlike the leaked ISOs and Upgrade Assistant from earlier this week, this ISO release is official but they should still be considered pre-release software. That means this Build 15063 ISO should not be used to upgrade all of your devices unless you are in the Windows Insider Program.
On the Mobile side of the Creators Update, the first cumulative update was pushed out two days ago. This patch was sent out to Fast Ring Insiders and insures that those handsets can upgrade from the Anniversary Update (Builds 14393.xxx) directly to the Creators Update (15063.xxx) in one step. Without this patch, according to Microsoft, Windows 10 Mobile users would have to first upgrade from 14393.xxx to 15051 and then to 15063.xxx. This same patch was pushed out to Slow Ring Insiders for their Windows 10 Mobile devices yesterday.
The next thing to be on the look out for is a cumulative update for PCs that should roll out to Windows Insiders in the Fast Ring first and then very quickly thereafter to those in the Slow and Release Preview Rings. That patch will address any lingering bugs or performance issues prior to the start of 11 April roll out.
On a related note, it also appears that app updates are finally rolling out to devices running 15063 in the Fast Ring. Previously those updates were only targeting Slow Ring and Release Preview installs. This means you should no longer have to switch to Slow/Release Preview Rings just to get the app updates and then switch back to Fast Ring afterwards.