Blogs.EastonBaseball.com is a great example of using WordPress MU to develop a site with complexity that is easy to use for a non-technical writer. Each blog on this site has its own personality. The graphic design of the home page of Blogs.EastonBaseball.com is different from that of each of the individual blogs.
Each individual blog is a fully-functioning WordPress blog that is linked to every other Easton-Bell Sports website, yet can be managed centrally from the WordPress MU interface. EastonBaseball can easily add additional blogs as needed.