As I mentioned earlier the upcoming release of Opera 9.5 comes with 2 long awaited features: SVG as background-image (CSS), and SVG via <img/>. The alpha versions were buggy all over the place, but the freshly released beta seems to be pretty stable.
So, what is it good for? Good question. I also wondered about that. This is what I came up with:
Be sure to check out the the resize and zooming behavior. It's pretty nifty.