You are overestimating the power that the standards board has over what browser vendors choose to include in their software. What you are asking of them is not really in their power. Besides, if VMs can make the W3C irrelevant, then they will do so regardless of W3C's approval of any particular standard.

For what it's worth, we're already very close to the point where "a language creator can sit down and create a new language and UI framework universally for browsers".