I think the real unanswered question is:

can the server dll for remoting be deployed "alone" without copying side by side any external reference to the dll where interface is applied ?

I mean, the server do incorporate the interface statically (so IMyFooClass.dll do not need to be copied), and the client do use remoting with a reference to the same IMyFooClass.dll.

Also, may i use some "standard" class, like an Hashtable, to be registered by the service and send informations to client wothout requiring any reference that need to be added on both client and server side ?

I'm looking for a way to decoupling server and client development, without sharing any common types libraries, but using only standard types like expando objects, collections, hashtables, and so on