Hi rsrgc,
How are you? I am still here, still waiting...
Regarding your question, it depends on your friend's current service center (NSC). Each service center behaves in a different way! One of the following could happen:
1) Just simply they approve the case.
2) Transfer the case to current local INS.
3) Do service center level transfer (NSC->CSC)
If it is CSC they will do one of the first two (#1 or #2)
If it is TSC they did #3 in couple of cases which messedup the case(s) a lot and it took few months for that applicant(s) to figure out where exactly the case is at that time.
I don't know much about NSC and I think it could do any of above three.
Also note that even though your friend files AR-11 to notify address change they may not check it until they are ready to send any communication to your friend and by then they may approve the case...
-PCee