Zitat: "The working group published the First Public Working Draft of the specification on January 22, 2008.[1] The specification is ongoing work, and expected to remain so for many years, although parts of HTML5 are going to be finished and implemented in browsers before the whole specification reaches final Recommendation status."
Zumal HTML5 in Sachen Parsing ein Rückschritt ist, da es nun mal den Nachfolger von HTML 4.01 darstellt und nicht zur XHTML-Reihe gehört, also nicht mal well-formed sein muss.
Quelle: Wikipedia
HTML5 scheint also nicht so ganz die Lösung zu sein...