The only thing I disagree with this plugin is the title: it's not yet just another related posts plugin, it's the best one available, IMHO.
The quality of the related posts is remarkable. There are options to include related posts links in both feeds and on-site. You can even change the markup of the generated list.
If there's one thing that this plugin is missing, it's support for post thumbnails on the related posts. Otherwise, great plugin. I use it on almost all of my sites.