HTML is all about Hyper Text Markup Language, "HTML5" messed up the basic conception by introducing these video and audio stuff. If this isn't enough it's using computer resources inefficiently in my opinion (those web browser applications). It's gonna be new Flash because of this (because what is the difference between browser application and Flash program?)
The Amiga browsers should avoid such contents and stay in good HTML4 standards, thus being quickest web browsers in the world (IBrowse)
As of TimberWolf or OWB they should also avoid newest standards, because we haven't granted access to the most recent hardware right now.