Mozilla does a great job promoting open web standards and Firefox is the one of the best footholds the community and industry have against hegemony and stagnation online.
However other organizations can and do work towards the same goals. I'm one of the creators of Tent[1] which shares a lot in common with Persona (including some community members) but is more ambitious in many ways.
In the Persona AAR Mozilla identified several reasons for Persona's failure to gain adoption[2] including that Persona " can't offer the same [as Facebook Connect] incentives (access to user data)". Tent's primary purpose is as a user data store and also supports features like address changes automatically (which Persona never did).
We were fans of and friendly with the Persona team, but I believe the best solutions to these problems will come from teams that aren't afraid to think bigger than Mozilla's strategy at the time allowed.
The work of federated identity solutions will continue on Tent and other projects, many of which are probably better suited for a wide variety of users and products than Persona would have been. Of course none of us have (or are likely to gain) the level of institutional (or financial) support that Persona had.
[1] https://tent.io
[2] https://wiki.mozilla.org/Identity/Persona_AAR