This seems to require prior knowledge of the connectors defined and what they mean. While this is, most likely, where the majority of development would happen (in-house against your known targets), I don't see how the later examples (/actors/<id>) would work. Unless Jangle defines a default target, then we're golden.

Jangle defines routing to a connector and each connector implements the same set of services. The connector itself could provide a registry of the services it provides, which Jangle could present for a client to select from (e.g. in WADL).