I actually tried for hours and hours to get this working natively in IE with VML (which is what excanvas uses behind the scenes). Unfortunately, it is just WAY too slow (each pixel becomes an "object" in VML space -- yeech). So I had to cheat with Chrome Frame for now. I am looking at implementing this in Flash for IE 6/7/8 (should be totally possible with their high performance BitmapData and ByteArray objects in ActionScript 3).