One of the “few abstractions to work comfortably with the SVG DOM” that “you can easily write […] as you need them” would be a layout engine. You need one to adjust your UI to the user’s screen size.
Another, I think, is that, to add scroll bars to a view, you have to write SVG scroll bars, make them respond to the mouse scroll wheel, be accessible, etc.
Even if we will get them, eventually, it won’t be “easily”.
I think it is easier to use HTML for layout, and SVG (or canvas) for those views that need it. You can do that now.
Absolute positioning gets a bad rap! And yes, if you want widgets then you have a lot of work ahead of you. But it's a lot of fun to just work with the primitives - don't believe them when they tell you always need a GUI toolkit!
