The latest version of the InfoCard integration guide calls out a problem that I groaned about earlier:
IMPORTANT NOTE: Notice that the URI used as the value of the ValueType attribute on the wsse:KeyIdentifier element to indicate a SHA1 thumbprint based key identifier is a slightly outdated URI value. The new prescribed value as per the WS-Security v1.1 standard should be as follows:
Support for this newer URI will be added in a future versions of the Information Card Profile.
So as much as I would like to think that someone out there actually listened to my complaints, I realized that this was probably documented before I said anything. Oh well.