W3C is working to transition the Web to XML, and XHTML 1.0 is the first step as a reformulation of HTML4 in XML
The increasing variety of browser platforms motivates the development of ways to subset and extend HTML
We have started by modularizing XHTML 1.0 using DTDs
XML Schemas will give us greater expressivity for modules
Content providers will be able to use document profiles to further ensure that their content will be rendered as expected
Work on extending HTML has not stopped, and we are working on adding support for DOM2 events, Ruby, and XForms
W3C's work on vector graphics (SVG), animation and multimedia (SMIL-Boston), math (MathML), DOM, etc. offer an exciting leap forward for the Web.
W3C is poised to define document types that combine this family of tag sets to set the standard for the next generation of Web browsers