The following information helps you decide whether enabling Web Services Federation between ADFS and OpenSSO Enterprise is suitable for your needs.
You are likely to leverage WS-Federation in a mixed environment involving Windows domains and heterogeneous web service environments. In such cases, using WS-Federation eliminates the need to complete the complicated setups involved with Desktop SSO (IWA, Kerberos, etc.). This simplifies the integration of web services in the ADFS-based environments.
The immediate benefit is the single sign-on to SharePoint Services from non-ADFs environments. This can be extended to pure claims-based applications residing inside the Resource Partner's domain.
The main drawback to using WS-Federation is that currently only limited support or configuration help is offered for ADFS claims within OpenSSO Enterprise. For example, the Microsoft Administering Active Directory Federation Services Guidehttp://technet.microsoft.com/en-us/library/cc736337.aspx depicts the use of group claims and their mapping between realms. The use of group claims eliminates the need to map user principals information from one realm to the next in a federated environment. These claims, based on group memberships, have not been tested in this deployment example configuration.