It's cyclic.
The market for doctors is fairly constant, it's very difficult to mint new doctors. Even if a state or university went through the enormous undertaking to create a new med-school, they would, at best, create 200-300 new doctors a year, a drop in the bucket.
The real solution is in alternative degrees like Physician Assistants or Nurse Practitioners. They can get degrees at half the cost of doctors and yet do 80% of a doctor's work.
Any real cost reductions in U.S. healthcare will have to include these alternative healthcare providers.
In USA. Definitely not in EU (currently, although there is a increasing pressure to dismantle and privatize university)
On the other hand, robotic solutions are competing for more and more roles in Hospitals. We have robotic helpers for surgeons yet. At some point in the near future they will start replacing many people and this factor should be included in the picture. Specialists will do online surgeries in all country without spending the time traveling from one hospital to other. The future can need less doctors for treating the same people.