Good presentation last week at CIS 2012 from Vikas Jain on the scenarios for leveraging OpenID for IDaaS models.
There are many emerging applications for using OpenID in this way and Vikas talks about a number of use cases for the Enterprise including:
Front-end authN into IDaaS using OpenID
SSO to OpenID Protected Apps from IDaaS Portals
User Verification of Street Identity
He also spoke about use cases for Service Providers who interact with both Consumer and Enterprise Users.
See the presentation: Leveraging OpenID within an IDaas Model.