“Wanna know how I can tell that no other browser vendor participated in the creation of the new meta X-UA-Compatible tag? Because it’s completely worthless – and in fact harmful – for any browser to implement!”

“By contrast, the many developers who don’t understand or care about web standards, and who only test their CSS and scripts in the latest version of IE, won’t opt in, so their stuff will render in IE8 the same way it rendered in IE7.”