Thanks, Sam for kicking this off - I knew it was just a matter of time before someone would do a proof-of-concept, but the week of MIX07 was earlier than I expected! 🙂

One suggestion: If you're going to use simple IE detection, then why not use IE conditional comments rather than forcing other SVG-capable browsers to load and parse and run the JavaScript? Something like:

<!--[if IE]>
  <script type="text/javascript" src="SVG2SL.js"></script>
<![endif]-->