My site is using the offical WordPress MU version, but the themes available aren't really that interesting for what I have in mind. That's why I've hacked the hell out of one of my favorite themes for the main page.
Quote: "I'm not shooting the idea down - a community blog sounds like a GREAT ideal, but its not anything 'special'. What could make it stand out from Blogger/Wordpress/own install of a blog."
The difference I'm hoping to achieve is a more interactive blogging community. There are tons of developer blogs all over the internet, but they are usually solo blogs. The author has really no idea if people actually pay attention to what he/she posts. A community of bloggers that share similar interests, and using the design I'm proposing, the exposure a blogger has will be much greater. An author that has more interaction with members will be much more motivated than one who flys solo.
Also, WordPress MU creates a new user blog when a person joins the site. They have the ability to customize their own blog to their liking, even activing the plugins they'd like to use. Pretty good for a free site.