It's Cory's world, we just live in it

I was rereading http://www.oreillynet.com/lpt/a/network/2002/03/08/cory_google.html by Cory Doctorow (after following Scott Rosenberg’s link to Andrew Googman on the death of metatags.
As I mentioned in Scott’s comments, it’s keyword metatags that have the least efficacy and the most potential for gaming of indexers, although I agree with another commenter who suggested that they have a valid use in providing synonyms for words actually present in a document, especially in an intranet context.
Cory’s essay talks about how Google’s “who’s linking to it?” formulae are more effective than the process of manually indexing a repository based on metadata and human editorial judgement.
While I believe in trying to solve the problem from both directions (make it easy for people to add metadata when contributing content and also don’t expect metadata to be there when you are searching), I do think that meta tags make sense most of all in closed system, as when indexing an intranet, in which you can control what meta data is applied and then do specific parameter-matching searches.