Hi Kroc, this could be the wrong section as u state u will be only supporting IE9 in the new version. After implementing the use of ur remarkable script I had problems that the CSS was broken in IE8 and below because it would not understand the html 5 tags and hence not apply the child selector css - I noticed a similar behaviour or unstyled view on ur page and thought I might share the solution to the problem:
<!-- concept taken from: webmonkey.com/… -->
<!--[if lte IE 8]>
<script>
document.createElement('header');
document.createElement('nav');
document.createElement('section');
document.createElement('article');
document.createElement('aside');
document.createElement('footer');
</script>
<![endif]-->
I hate creating support for browsers I do not use but still many people use at least IE8 ;)
Greetings
Raj