In your latest example I'm getting a steady 35 FPS in FF 6.01 and a steady 48 FPS in IE9.
This is on an i7 930, 6gb RAM, ATI 5870 and Win 7 64 bit.
Great work by the way, looking forward to the release!
Thanks! The plugin running the calculations without rendering the shadows etc runs at 60fps so the actual performance is really good just can't seem to increase the rendering speed of the shadow <img src="smileys/smiley7.gif" border="0" align="middle" />. I know eventually rendering will be alot faster and WebGL will pop up at some point...
Currently fixing some small bugs, cleaning the code. It will probably be a behaviour attached to objects so you can have more than one light/sight.
Here's another example I'm working on:
<img src="http://dl.dropbox.com/u/19078872/test.png" border="0" />