Major Description
According to the WS-Federation Standard 1.2 [1] the ApplicationServiceEndpoint should "provides a transport address for the application service". The current implementation uses the realm identifier which does not need to be a transport address. (as it is the case in the fediz hello world example)
[1] http://docs.oasis-open.org/wsfed/federation/v1.2/os/ws-federation-1.2-spec-os.html#_Toc223174945 3.1.2.5 ApplicationServiceType