A very simple change to the Blogger template finally made this blog look a lot better in IE 9, which supports rounded corners and several other CSS3 styles.
Blogger adds two things to the template's <head> tag that interfere with IE9's native support for CSS3:
<meta content='IE=EmulateIE7' http-equiv='X-UA-Compatible'/>
This meta tag is needed for IE8 and earlier and is visible in the blog template editor.
<!--[if IE]><script type="text/javascript" src="http://www.blogger.com/static/v1/jsbin/2846761551-ieretrofit.js"></script>
<![endif]-->
This conditional is not needed for IE9, but it's also not visible in the blog template editor, so you can't change it to [if lt IE 9] instead of [if IE].
The Simple Solution
Edit your Blogger template to add a new conditional X-UA-Compatible meta tag for IE9 and make the existing X-UA-Compatible conditional for IE8 and under. Please back up your template before making changes to it. Then make the following change in the template's <head> tag:
Find and change this:
<meta content='IE=EmulateIE7' http-equiv='X-UA-Compatible'/>
To this:
<!--[if lte IE 8]> <meta content='IE=EmulateIE7' http-equiv='X-UA-Compatible'/> <![endif]-->
<!--[if gte IE 9]> <meta http-equiv='X-UA-Compatible' content='IE=9'/> <![endif]-->
Save changes and view your blog in IE 9. It should look spectacular!
