Well, the switch has happened this morning (2015-07-15): Fedora Infrastructure upgraded the authentication infrastructure, which is the web application that does the authentication of users for our web applications, from FedOAuth
There had been an outage scheduled this morning at 08:00 until 10:00 UTC this morning for the migration, and at 09:30 the OpenID services were all back available and at 10:00 all services that Fedora Infrastructure runs were working again!
(Persona took longer due to a mistake on my part with published public keys not belonging to the keys actually used, sorry for that).
Now that we have switched to Ipsilon, I will be working on some other projects to improve the authentication infrastructure in Fedora, like Single Signon (just one time logging in will get you in on all of our applications) and Single Logout (logging out on one place logs you out on all of our applications).
Please look forward to more announcements in this regard!
This also marks a major milestone for the Ipsilon project: as far as I am aware, this is the first major production instance of Ipsilon.
Let's see how well it will hold up!