This is a big (and half-baked) idea. While I think pagure is awesome, I have two big worries about it overall:

1. Not getting enough momentum to attract external contribution and become a successful project outside of Fedora
2. OMG we've gone and created yet another issue tracker for Fedora, because bugzilla, trac, mediawiki (!), github, jira, weren't enough :)

So, what if, instead of focusing on stand-alone functionality, pagure became a module of project-management system taiga.io? We're experimenting with taiga for Fedora Rel Eng, and if that's successful, probably beyond that. And Taiga:

• Yes, of course, has an issue tracking system of its own
• Does appear to have some momentum (e.g. hey look Fedora is interested), although it's not yet huge
• Has a modular structure — features like a scrum board, rudimentary wiki, the issue tracker, etc., can be enabled and disabled
• already has fedauth integration :)

As I said, this idea is half-baked.

One possibility would be for pagure to remain primarily stand-alone, but to develop an integration module. Replacing Redmine (which is a kind of uber-meta-trac, if you haven't seen it before) seems to be a general Taiga target, and Redmine has a repo viewer built in, and maybe this could be just that. I see that there is already github, gitlab, and bitbucket integration, but I don't actually know what that means yet.
Ideally in this case the issues would be synced between the two systems.

Another possibility would be to go all-in and integrate the pagure front-end completely into Taiga's. This is bigger and more invasive, but on the other hand makes questions like "how to sync issues" straightforward.