Have you considered refreshing this 'map' periodically and/or adding this to either the Clojure website or wiki? I think that'd be a nice way to help people stay abreast of useful up-and-comers.
The vast majority of Clojure projects all seem to live on github. So, perhaps one way of picking out important projects with one/few contributors could be by looking at projects with high numbers of forks or watchers?
For now, I need to focused on improving my calculations, fetching all the data I need (what I showed in the article is just the tip of the iceberg), and finding better ways to infer relationships between projects.
Can't wait to see what you come up with. Best of luck!
Starting out with Ruby/Rails can be quite daunting, not so much because of the language or the framework but because of the ecosystem with it's many third-party tooling.