Metasystem-schmetasystem

Premise: a single identity 'session' theoretically (a real instance would be unlikely to have them all) consists of the following stages:

1. Authentication
   
2. Single SignOn
   
3. User-agent mediated attribute exchange
4. Server-to-server attribute exchange
5. Single Log Out

Our various identity systems can be categorized as to whether they address the 5 stages. My best guess

Authentication

• Cardspace
• ID-WSF

Single Sign On

• OpenID
• SAML
• Cardspace (smart client)
  
• ID-WSF (smart client)
  
• WS-Federation

User-agent mediated attribute exchange

• SAML
• Cardspace
• OpenID (Attribute Exchange)

Server-to-server attribute exchange

• ID-WSF

Single Log Out

• SAML
• WS-Federation

Only 60 combinations to work out. Easy peasy.