actually, this may fix the 2d cross platform issue; kind of like flash did in a way. If there are a few frameworks that render html in a flat plain inside of a canvas, or inside of webgl. This creates a virtual browser of sorts. Then developers that use those frameworks to render their designs, will be guaranteed consistency across browsers. The rendered result can and should look like any rendered site, at first; but I'll get to that later.
This also allows framework designers to attempt better standards compliance with less limitations. This might even fix the DOM issues that developers bump up against; they could build a more optimized dom, or fix it.
Once that move has been made, to the 2d plain in 3d space. Then we can take our webgl browser and move it into more interesting spaces. That's when things get fun for me.
Now imagine this running on a chromebook, or the new firefox driven distro out there. These are geared directly towards the web and a combination of webgl and our browser could give better OS contextual switching between browsing and an app or game.
Just food for thought.
Also, VML kind of sucked back in the 90's.