Update A-grade browser support
IE6 is especially deficient, as I expect you know. It is undeniable that these deficiencies hold back good improvements for the other ~98%. The deployment of class="hlist" on en:wp (w:en:WP:HLIST, horizontal list styling in navboxes) is a good example. IE6 support is via js, which bogs down on larger pages (it's supporting IE7&8, too). It's quite possible that IE6 will linger indefinitely at something a hair above 1%. Mostly it's pirated copies in China on XP. Most people in the developing world are jumping at the various modern-and-free browsers. That 1% set in stone? Oh, and thanks for the 2.22% data point. Good to know.
If the English Wikipedia doesn't want to support IE6, that's up to them. They can make the decision to drop hlist support for IE6 if it's so much of a hassle.
If IE7 & IE8 don't need it to be done through javascript, there's no reason to do the javascript fallback in them, too. At that point, it would only "bog down" those users that you are proposing to leave with no support at all.
