In March, Microsoft announced that their upcoming Internet Explorer 8
would: "use its most standards compliant mode, IE8 Standards, as the
default."

Note the last word: default. Microsoft argued that, in light of their
newly published interoperability principles, it was the right thing to
do. This declaration heralded an about-face and was widely praised by
the web standards community; people were stunned and delighted by
Microsoft's promise.

This week, the promise was broken. It lasted less than six months. Now
that Internet Explorer IE8 beta 2 is released, we know that many, if
not most, pages viewed in IE8 will not be shown in standards mode by
default. The dirty secret is buried deep down in the «Compatibility
view» configuration panel, where the «Display intranet sites in
Compatibility View» box is checked by default. Thus, by default,
intranet pages are not viewed in standards mode.


http://www.theregister.co.uk/2008/08...eroperability/