One thing i'd like to see is an entire site built with SVG and JS without any HTML at all. It's possible but i haven't seen anyone do it yet.
I've used SVG in the past to work around limitations in css alignment (cloth before and after new layouts made it unnecessary--I don't write CSS enough to remember how they work, but adding text to a quick drawing in inkscape is fairly trivial)
so how can you know it's actually possible?
Browsers will render SVG files. SVG files can link to other SVG files. Just need to configure the server to serve SVG by default — most servers don't but it's an easy config change.
Actually just found one, via an old stack overflow post. Only a three page test, but proves the point: