Don't get me wrong. I have not done anything yet for the 7000ES for the Pronto. I just wrote a PC based system as a proof of concept (I code and debug much faster on a PC). The answer to your question however is yes. The basic IP interface is independent of the "Skin". The 7000 changer has a built in library which is really not very exciting. I have a librarian that I have released for the Pronto that is actually player independent as most movie librarians are.

You could keep the two activities; the librarian whose job is it is to come up with a changer slot number; and the changer control activity whose job is to take the slot number, start that disk playing and provide transport control.

That is exactly the way my Home theater system works but has a PC in the loop instead of extenders.