On his blog, Rob Richards reintroduces a library he's written (xmlseclibs) to work with information cards with a missing piece from the example code he provided before.
There is, however, a missing piece to the managed code example I had posted, which I am finally getting around to talking about. It is the Infocard Managed library file (icard_managed_lib.php). This library provides the functionality needed to create a managed card that a user can download and install.
He also includes the different classes that the library uses to create the information cards including ICard, ICardClaimType, ICardUserCredential and ICardSAML.