Last modified: 2009-08-10 17:50:01 UTC
According to wikipedia, <a href="http://en.wikipedia.org/wiki/XHTML#The_XHTML_2.0_draft_specification">XHTML 2.0</a> will take another while to get drafted. XHTML will result in a major break in terms of compatibility. We won't have mainstream browser software for XHTML 2.0 in 2006 if everything goes planned. This feature request is a rather hard one: A lot of tags will be replaced from our current output. Complying to XHTML 2.0 means rewriting almost every output related part of the Mediawiki code, AFAIK. This is the <a href="http://www.w3.org/TR/2005/WD-xhtml2-20050527/">future</a>....
from what i can gather xhtml 2 in its present form is basically unusable due to the fact it doesn't allow pages to be authored in a backwards compatible manner. if/when xhtml2 becomes useable this can possiblly be revisited but i see any need/reason for mediawiki to be an early adoptor.
I'm gonna go wild and resolve this as LATER, which we haven't used much before. ;) Generally speaking I don't think supporting XHTML 2.0 will be all that difficult -- mostly it should be a straightforward transformation of existing markup to new variants. Aside from the fact that there's no point in it until there's widespread browser support, the main technical obstacle is that we still don't guarantee well-formed XML output to begin with. Until the parser can guarantee proper nesting of elements, there would be little point in expending the transformation effort either.
HTML5 FTW