That's horrible. Instead of drawing graphs on the client side, you're pushing insanely large number of images to the browser. It makes sense for google maps, not for graphs.
Plus you can't do any animation, changes to the graphs on the fly.
The idea that Seadragon is a platform that can be compared with Flash and Canvas is such crap. Its just a library for zoomable maps (which you've been able to create for years with the google maps API since 2005 or something).