I was just reading Wikipedia's section on XHTML 2.0. To me it looks to be a great release! I hope the browsers can adopt it as soon as it's released. Although knowing Internet Explorer we won't be able to use it for another 5 years.
Work on XHTML 2.0 is, as of 2007, still ongoing. The current XHTML 2.0 Working Draft is controversial because it breaks backward compatibility with all previous versions, and is therefore, in effect, a new markup language created to circumvent (X)HTML's limitations rather than being simply a new version. Many issues with compatibility are easily addressed, however, XHTML 2.0 can currently be parsed the same way a user agent would parse XHTML 1.1: via an XML parser and a default CSS document conforming to the current XHTML 2.0 Working Draft.
New features brought into the HTML family of markup languages by XHTML 2.0:
HTML forms will be replaced by XForms, an XML-based user input specification allowing forms to be displayed appropriately for different rendering devices.
HTML frames will be replaced by XFrames.
The DOM Events will be replaced by XML Events, which uses the XML Document Object Model.
A new list element type, the nl element type, will be included to specifically designate a list as a navigation list. This will be useful in creating nested menus, which are currently created by a wide variety of means like nested unordered lists or nested definition lists.
Any element will be able to act as a hyperlink, e.g., <li href="articles.html">Articles</li>, similar to XLink. However, XLink itself is not compatible with XHTML due to design differences.
Any element will be able to reference alternative media with the src attribute, e.g., <p src="lbridge.jpg" type="image/jpeg">London Bridge</p> is the same as <object src="lbridge.jpg" type="image/jpeg"><p>London Bridge</p></object>.
The alt attribute of the img element has been removed: alternative text will be given in the content of the img element, much like the object element, e.g., <img src="hms_audacious.jpg">HMS <em>Audacious</em></img>.
A single heading element (h) will be added. The level of these headings will be indicated by the nested section elements, each with their own h heading.
The remaining presentational elements i, b and tt, still allowed in XHTML 1.x (even Strict), will be absent from XHTML 2.0. The only somewhat presentational elements remaining will be sup and sub for superscript and subscript respectively, because they have significant non-presentational uses and are required by certain languages. All other tags are meant to be semantic instead (e.g. <strong> for strong or bolded text) while allowing the user agent to control the presentation of elements via CSS.
The addition of RDF triple with the property and about attributes to facilitate the conversion from XHTML to RDF/XML.
The man who comes back through the Door in the Wall will never be quite the same as the man who went out.