Most of the work has finished: people are using the specifications in production and the rate of errata has slowed to a crawl. XQuery, XSLT and EXI ended this year. But just because the specification work is ending doesn’t mean XML is ending! It means XML is at a stage where the technology is mature and widely deployed. People aren’t reporting many new problems because the problems have already been worked out.
—The World Wide Success That Is XML, on the W3C Blog.