Below is a customized home using the default Kubrick theme...simple, but effective for what I want. On the "List of All Blogs" page, I actually incorporated the blog description based on your question...hadn't thought about it until you mentioned it.
http://kentuckyclassroom.org/
Here is test site with another theme with some basic stuff like latest posts, newest blogs, and latest updated included. I haven't figured out how to call latest comments yet...
http://stevehyndman.com/
You may want to take a look at the posts in the "Your WordPress MU" where people include links to their Mu sites. You will see some pretty cool customizations there.
http://mu.wordpress.org/forums/forum.php?id=11&page
Bottom line though...you can start with just about any theme as your site theme and then customize to fit your needs...you don't need to stick with the default Kubrick theme.
Steve