I had a query the other day to validate if WIF (windows indentity foundation) was actively used in a MSCRM 2011 implementation configured with windows authentication (ie: Kerberos).
Now, WIF is a required component of the server installation, of the Outlook addin installation and of the SDK (see this article), but that does not means it is actively used in a non claims based mode.
Looking in the Claims authentication white paper, I found this little note :
Microsoft Dynamics CRM Server 2011 replaces forms authentication with claims-based authentication, an identity access solution designed to provide simplified user access and single sign-on access to Microsoft Dynamics CRM data.
Interoperability is provided through reliance on industry standard protocols such as WS-Federation, WS-Trust, and Security Assertion Markup Language 1.1 (SAML)."
Actually, the data flow for Windows authentication in the white paper is exactly the same as for MSCRM 4.0 (or any standard asp.net windows authentication by the way), so no need to involve another technology