The IE guys are saying this needs to be kept for backwards compatibility. http://www.w3.org/Bugs/Public/show_bug.cgi?id=11960#c8

Why can't it be kept for old doctypes and quirksmode like Gecko does? The HTML5 doctype should get rid of this. Surely that wouldn't break top sites as MSFT is saying: http://www.w3.org/Bugs/Public/show_bug.cgi?id=11960#c12