Similar to the redmine plugin, but for trac projects.
Yes, I'm also looking for that feature.
I've started to create a library at https://bitbucket.org/sdorra/javatrac, which is a fork of https://code.google.com/p/tracdrops
Plugin repository is located at https://bitbucket.org/sdorra/scm-trac-plugin
The plugin is now available via the plugin center. The plugin requires at least version 1.33 of SCM-Manager.