I think to better tackle this task of analyzing XHTML 2 and HTML 5 it would be best to describe some characteristics of each and then allow you to come up with your own conclusion on each language. The reason being is that each has it’s own pros and cons.
Backwards Compatibility with XHTML 2
Because earlier versions of HTML were special-purpose languages, it was necessary to include a level of backwards compatibility with new versions so that new documents would still be usable in older browsers. Now with XML and style sheets, strict element-wise backwards compatibility is longer required. This is because of XML-based browsers that when at the time the article was written means more than 95% of browsers in use, are capable to process new markup languages without having to be updated.
Presentation
HTML at its core is a document structuring language. XHTML 2 takes HTML back to these beginnings by getting rid of all presentation elements and putting them in a style sheet. This gives greater device-independence and presentation ability to the document since style sheets can do more for presentation than HTML ever was capable of. Although, HTML does offer presentation markup unlike XHTML. Which I guess depending on preference and usability, may be a good or a bad thing.
W3C HTML 5 document stated that “XHTML2 defines a new HTML vocabulary with better features for hyperlinks, multimedia content, annotating document edits, rich metadata, declarative interactive forms, and describing the semantics of human literary works such as poems and scientific papers.”
XHTML 2 lacks elements to express the semantics of many non-document types of content that is often seen on the Web. For example, forum sites, auction sites, search engines and online shops do not fit the document metaphor well, and are not covered by XHTML2.