status-completed (as of rev 2015.7.13.3577 on meta, 2015.7.13.2722 elsewhere)
That's great! So, let's go to some site where I don't have an account (but actually I do have everywhere, so I had to delete one of the unused :D)
If you are on the main site, you can see:
But if you are on the per-site meta, you'll see the usual "sign up / log in":
Though it's possible to click "log in" which takes you to the main site login and then click "join this community", maybe I should be able to directly use the new "join" feature from the per-site meta too?