SelfSTS is an extremely useful application which simplifies WIF testing by allowing you to define claims without an instance of AD installed.
Given that it supports the WS-Federation protocol, it should in theory be able to be federated with AFDS v2.0. However, in practice, it doesn't fly. ADFS complains that there are unsupported elements in the federation metadata. If you try and import the metadata via a file, ADFS complains that only https URL's are supported. SelfSTS has the common or garden http URL.
However, this article shows how to federate SelfSTS with Azure's Appfabric ACS. Since you can federate ACS with ADFS, you can essentially get the federation working - albeit in a round-about way.