Secunia Refutes Microsoft IE7 Argument

This may be true - from an organizational point of view within Microsoft. However, the vulnerability is fully exploitable via IE, which is the primary attack vector, if not the only attack vector.

Just because a vulnerability stems from an underlying component does not relieve IE or any other piece of software from responsibility when it provides a clear direct vector to the vulnerable component.

Hiding behind an explanation that certain vulnerabilities, which only are exploitable through Internet Explorer, are to blame on Outlook Express, Microsoft Windows, or other core Microsoft Windows components seems more like a way to promote security of IE rather than standing up and explaining the users where the true risk is and taking responsibility for the vulnerabilities and risks in IE, which are caused by IE being so heavily integrated with the underlying operating system and other Microsoft components.