Keyboard events work the same on IE as they do in every other browser, so that wouldn't be an issue. The demo does not appear to be doing anything subtractive,

Keyboard events work the same on IE as they do in every other browser, so that wouldn't be an issue. The demo does not appear to be doing anything subtractive, which is the only piece of 2D vector stuff that VML doesn't do (and therefore that excanvas doesn't handle automatically). So long as they're just drawing shapes on a canvas, it should simply start working once they include the excanvas script.