Some developers have requested more time to complete this transition, so we've decided to extend the window until May 1 before we start enforcing this policy for the Windows Stable channel. As a reminder this policy will only apply to Windows Beta and Stable channel users. You can continue to use off-store extensions on Windows Dev and Canary, as well as on Mac, Linux and Chrome OS. Developer and enterprise policy use cases are similarly unaffected.
To minimize potential disruption to your users, please be sure to register your extension in the Chrome Web Store before May 1.