I am using my own custom-built blog -
http://www.extremefitness.com/blog (based on the PhotoPost code base).
Basically what's missing from the vB version is the ability to group blogs into public categories. Many of our users like to be able to look at other people's blogs and do so according to the topic (like Bodybuilding Blogs for example).
I think what's needed are "public categories" where a user can associate their blogs to that public category and then people can click on that category for those blogs associated with it. Otherwise everyone's blogs are just out there are not connected in any way.