You are right, Deloitte UK owns Deloitte Switzerland. In fact, they are giving it a good push for it to grow (its virtually non-existent over there).
- Most (if not all) of the work is in Zurich
- For people based in zurich you have to speak german, in geneva's case french is required.
At least, this is what I have heard (and seen on the job requirements webpage).
Thanks anyhow for your input giacamo. :)