From :Column Two: Death of keywords:

To me, this really highlights the challenges (futility?) of the so-called “semantic web”, where everything describes itself, cross-linking happens automatically and accurately, and search engines only return useful results…

If we can’t get even simple keywords tags to work in practice, what hope is there for RDF, and the rest?

My own opinion is that any acitivity or tool that requires consistent, similar, behaviors across the entire Web (such as accurate keywording of web pages) will not happen.

However, that doesn’t mean the keyword metatag is dead. It can still be an effective tool for a collection of content whose authors/owners are willing to invest time and effort into for accurate searching and indexing. The Web might evolve into small, organized, clusters of content that create semantic islands in a chaotic sea.