I've been thinking a lot about how I'd go about making the social network visualization idea into a useful piece of software. I'm thinking it would be a plugin for Trac that would have a run-once analysis of the database (using one of the many free tools for generating social network data from emails) that spits out a social network graph accessible as a tab or subpage of the Trac web interface. It would then query the database daily for new information and add that in, though the complexity of adding new data to an existing graph might outweigh the benefits of not duplicating analysis if the existing software doesn't support that.
Now, a pretty graph is not too useful, so what else could you do? Well, there's the original plan we had of generating a code authorship network as well, overlaying them, and identifying some discrepancies as inefficiencies in the project that can be fixed by introducing people to one another or even restructuring teams. That sounds hard.
Even harder would be some sort of semantic analysis - I have a word cloud culled from emails and tickets relating to each person, and when I submit a ticket or send an email, it suggests more people to add to the recipient field based on keywords I've just typed.
Hmm, so I guess where I'm at is that I can see how to set up the basic system, but I'm not sure whether I can get more than one dataset so we can have comparisons and recommendations, rather than just straight up visualization of what's already happening. So, off to research! I'll check out the free tools on Wikipedia's page of social network analysis software, and start a search for what's been done in the way of repository introspection.