10 capabilities we want to see in HTML6 | InfoWorld
HTML/next - W3C Wiki
HTML6: The Next Big Thing After HTML5 | Top Design Magazine - Web Design and Digital Content
"W3C has chosen to make HTML5 a living standard and they are debating whether to drop the numeration all together, so we may end up not actually calling it HTML6 after all."
The main "innovation" in those proposals may be name "HTML6" :)
On more abstract level, "binding with remote data" may be promising.
If views / templates become available as Web Components, and data as Web APIs / services,
then the "controller" part may become main part of client-side web applications,
HTML6 innovation could be related to mobile and embedded applications,
with browser acting as "PhoneGap" by default, with secure control of API access and caching for each "App" / URL. That way many mobile apps could become web apps, with much easier distribution.
Web browsers could also act as "containers", with complete insulation of each tab/session. Access to local resources would be trough services / APIs, to significantly improve security...