This is for anyone who manages version of schematics/boards in git (like me!):
eagle-diff is a python script (and some simple configuration to your git repo) that will allow you to diff different versions of schematics/boards in a git repo. If you commit revisions of your eagle source files to git this gives you an easy and visual way to see differences of your schematic/boards.
Feedback is welcome. Send pull requests on github if you have suggested improvements.