I'm a bit more interested in what it teaches about the hyperbolic plane than I am in it's effectiveness as a note taking app (although the way it supports an exponentially growing tree does seem appropriate for depicting knowledge - I'd be interested to see something like a force directed graph of Wikipedia plotted on the hyperbolic plane).

The points and arrows do move and change shape appropriately while panning, but the images and text do not. It might be possible to use feDisplacementMap (an SVG filter effect) cleverly to get the deformations right. This would probably make performance worse, and I'm not sure how readable the text would be, but it would mean that things wouldn't start overlapping each other while panning.