The deepest cuts apparently will be at the World Service, which is tailored to an audience outside the U.K., and Radio 5, which is a talk and sports service. I'm not sure how Radio 5 will be affected, however, as news isn't a huge part of its format. Maybe its sports staff will be decimated. One would think that the eclectic Radio 4, with its broad assortment of documentary, discussion and entertainment programs, all produced and voiced in-house, would be a more inviting target.
I have a feeling the World Service was chosen because a large portion of its audience is not paying a dime to the BBC, being in the English-speaking world outside the U.K. Being a treasured source of information and entertainment is all well and good, but that won't pay the bills should the license fee go away.