Norm Walsh has published DocBook NG: The “PTO” Release; a.k.a. beta 14 of DocBook 5.0. DocBook NG is "a significant redesign that attempts to remain true to the spirit of DocBook." The schema is written in RELAX NG. A DTD generated from the RELAX NG schema is also available. "There are two significant changes in the 'PTO' release. First, the content models associated with sections have been reworked. Second, support for XInclude, first introduced in Mezcal, has been moved into a separate schema. It will be part of the DocBook schema distribution, but it will not be part of the normative DocBook schema."
Michael Smith has released version 1.69.1 of the DocBook XSL stylesheets. These support transforms to HTML, XHTML, and XSL-FO. This is a bug fix release.