What you see on dmoz.org is basically what you get in the RDF: category name, URL, site title, site description.
What the search engines DO with that is strictly up to them. AOL used to index category name, now they don't. Google never did, at least directly. I don't know of any major SE using site description or site title directly (unlike at, say, Yahoo, where sites whose description or title match your search are given high priority.) But since many SEs spider copies of the Open Directory, the directory pages with site descriptions and titles show up on many searches, which is even better for the user (they find the right category, no matter WHICH site's description happened to contain the particular synonym they used as a search key.)
AOL is of course in a state of flux right now; Google is always tweaking their algorithm. So any of this that happens to be true today, may be inoperative tomorrow. I'm not convinced the SEs have yet figured out how to get the full benefit of the RDF. [Teoma hasn't started using it at all...an oversight they will surely repair when they realize how much Google has benefited from it. Or they too will be crushed under the cycles of the googlenaut.]
I haven't kept up with inktomi, for some reason. I don't know whether it's because doesn't drive any major portals of any conceivable interest, or because their search results for reference-type searches never were any good anyway. I always felt like the query engine always added "& free spam!" to the end of my search string.
But I'm sure you SERP perps still want access to the audience held captive by MSN and/or the Infernal-Exploder-Invalid-URL scams, so this is valuable information.
Question, though: does Inktomi index the ODP descriptions for the ODP category page (like Google does) or for the home page of the listed site?