I can't understand why WPMU doesn't have an system to index blogs by subject matter. Is it so difficult to add database tables and dropdown boxes for users to select an area of interest when they signup and a script to list them on the admin page?
Having the ability for visitors to click on a link to view blogs by subject matter is a no brainer. It should be like walking into a library or store and browsing the aisles.
Using tags and searches is just too ponderous.