Danny Sullivan wrote a fantastic article describing some of the problems with using DMOZ data in search results. The article goes beyond just the limitations of using DMOZ data, and covers the general use of directories to supply results. Danny looks at results from Google, Ask, MSN, and Yahoo for a variety of permutations on specific searches.
The verdict? Directories have a wee bit of a tendency to be out of date. Sometimes several years out of date.
If there’s any reason that search engines should be convinced to provide exemption to the use of DMOZ information or information from other tags it’s the simple fact that they provide bad information. If search engines want to provide the best access to online resources, they need to do that at every step of the way. The information actually on the page is almost always going to be the most current information.
Directories can provide good value for a beginning to your inbound link building – but you need to keep on top of them, and update them every chance you can. And, with DMOZ – cross your fingers and hope that there’s still somebody actually managing that category.