What about the social bookmarking sites? Aren't directories just a bunch of organized bookmarks? What if you could take one of these growing social bookmarking sites, get some programming wiz to write an algo that can take some of the spamminess out of it and catagorize what s left? You then would have a site that could be called a directory as well as a way to search them based on tags.
I believe this is the next step forward in a directory, and would soon replace the ODP. Isn't that what the ODP is about anyway? A group of volunteers that adds their favorites for the rest of the net to benefit from? Only this way truly takes it to the next level. You would eliminate conflicts of interest that ODP editors have and have a much broader base of volunteers to get valuable links from.