FYI: when you say "on premise ArcGIS.com", I believe you are referring to Portal for ArcGIS, a new extension to ArcGIS for Server in the 10.2 release.
I found ArcGIS.com has support for MS Active Directory Federated Server ... However, our deployment will be �??on premise�?�. But still will require the ADFS support. ...
The current release of Portal for ArcGIS does not support SAML authentication. This is being considered for a future release. FYI, an ArcGIS 10.2 Server site can be registered as a �??federated server�??, with an on-premise deployment of Portal for ArcGIS.