There has been quite a lot of interest in code swarm recently. I took the Git VTK tracking repository Brad King set up, made a code swarm movie, and uploaded the results to our Vimeo account back in October. I updated the video just before the new year. Jeff Baumes told me that the author of code swarm mentioned the VTK code swarm during his talk at the Viz conference last year.
There is also a CMake code swarm, and more recently an ITK code swarm video. The names are those of developers that made commits to the repository, their name fades out as the time since their last commit increases. Files swarm around the developers as they commit changes to them, gravitating towards the developers that last committed changes to those files (dots). The histogram along the bottom shows the number of files in each category that were changed on a given day. I am also making a CMake code swarm movie. I can upload that to Vimeo too if people are interested. It is quite easy to generate these movies from Git repositories, I am using the a GitHub fork of the code swarm project.