Higgins has created a taxonomy of i-cards.
I believe the following captures the relationships as expressed.
In his recent announcement of about upcoming SAML support in Higgins, Paul suggests the possibility of an 'S-card', shown here
Where an S-card would be some XML instance pointing at a SAML IdP including necessary endpoints for the client to send/forward SAML protocol messages, with metadata about what identity attributes that IdP can provide, possibly with particular policy characteristics (e.g. security and/or authentication mechanism etc). Sounds likea a profile of SAML metadata.
NTT's SASSO 'SAML IDP on your phone' model balances things out nicely.