It is a nice idea but I can't get it to work with the Twenty Eleven Version 1.5 theme. It appears that if you want it to work with Twenty Eleven, there is a lot of code you need to rewrite somewhere (file not identified since the documentation refers to lines in the single.php file that may have been in an earlier version of the Twenty Eleven theme but are now nowhere to be found) and in the function.php file.
The documentation says it works without having to create dummy author profiles in your account but it depends on having the ability to have guest author profiles in WordPress.com, which you can't do unless you pay thousands of dollars for the WordPress AVI service in order to get the Guest Author Profile tool. Plus I don't see how those profiles can be ported over to a WordPress.org blog.
I did try reading several forum threads about it and tried some of their code but I usually ended up with an entirely blank page or the first author's name repeated such as "...by Author-1-First Name Author-1-FirstName and Author-1-First Name". Author-2 is not included.
Author boxes only show up when there is a single author. Nothing shows up if there are two authors.
I spent a lot of time trying to figure it out but ended up very frustrated. It needs more work to give it user friendly settings and to work with modern themes.