This plugin is really important for making WP more professional.
It seems to be almost working fine on WP2.7
There's an issue with using coauthors_wp_list_authors()
It does list authors with links, but this is only for the first author. The second or more authors do not show up. Even if you unhide them, their names remain no as links. This issue has been the case for previous versions of this plugin in earlier for earlier versions of WP.
(Note, using coauthors_posts_links() works fine).