The article said that the user-agent string was changing -- it said nothing about quirks mode going away. If you have an IE6-only intranet application, then by

The article said that the user-agent string was changing -- it said nothing about quirks mode going away. If you have an IE6-only intranet application, then by definition you are not depending on user-agent sniffing. In that case, you depend on the continued availability of quirks mode -- not on the user-agent string. If you have an intranet application that uses user-agent sniffing to support both legacy IE and standards-compliant browsers, then you should simply do nothing. The change in the user-agent string will cause Internet Explorer 11 to be treated as a "like Gecko" browser. This is as it should be, as IE 11 is a standards-compliant browser.