After last week's update I started to plan and code the proposed API following the scheme of the Forms API. This will provide developers with a very familiar way to construct graphic objects using the already known FAPI-like array structure. Right now the drawing_get_canvas is being worked on, this function is the core of the rendering, and is responsible to collect the objects, placing them on the drawing canvas.
My plans for this week are to implement more drawable objects and to finish the drawing_get_canvas function completely (handling callbacks for every object). I hope to release a tarball version of the project right before the next update, so interested people can check the features and the API.
Embedding currently works only in firefox, this issue will be addressed later. Simon started to the concept of an embedding API, that could provide us with a unified way to embed objects such as SVG graphics, audio, video and other stuff, Drawing API will probably support this at the end.
If you are interested, check out our group: http://groups.drupal.org/graphing-svg, and do not hesitate to share your opinion about the projects.