WordPress 3.2 has a new conditional tag that may come in handy for theme developers and users who are customizing multi-author WordPress sites. These are sites where the admin user is not the only one writing posts.
Here’s a new tool for your conditional tag toolbox: is_multi_author()
This template tag makes it easier for themes to have different behavior when a site has more than one author writing posts. is_multi_author() checks to see if more than one author has published posts for the site and returns true or false.