Single-user login[1] finalization will be taking place next month.[2] I know this has been said before over the past two years, but it is actually going to take place after nearly a decade of waiting :)
I just posted an important announcement about the renaming process itself on Meta.[3] If you're interested, please take some time to read it over and help translate if possible. A one sentence message about this has been sent to village pumps as well, where available.
All accounts that will be affected by this will be contacted on their talk page within the next couple of days.[4] All local wikis also have a publicly listed database of users who will be renamed, available at Special:UsersWhoWillBeRenamed.[4]
Thanks for your time, please help spread the word to your other mailing lists and/or communities.
1.
https://meta.wikimedia.org/wiki/Help:Unified_login