If you liked the functionality I described in vc-annotate, you might also like Syohei Yoshida’s git-gutter. It’s a port to Emacs of the Sublime Text plugin of the same name. The idea is that it marks changes to your files in the fringe so that you can see at a glance how the file is evolving. As the same suggests, it works only with git.
There are a lot of options that determine how the changes are marked so if you want fancy symbols instead of the traditional + or -, you can have them. Of course, you don’t get as much information as vc-annotate gives you but you can see what parts of the file have changed (and how) anytime you have git-gutter toggled on. In that sense, it seems like a nice adjunct to vc-annotate. There are screen shots at the link so you can get a sense of what it looks like in action.