For myself, it would take a lot before I would consider leaving medicine. I'm not a big earner, but then I practice a subspecialty that is characterized by few to no procedures, lots of phone calls and "face time"; basically, chronically disabled and ill kids. I rarely admit this as it hurts my sarcastic cred, but I love my job even while it gives me reflux; I love being able to make a difference for kids and their families and I would do it for considerably less money if I had to.
The rate limiting factors are time and quality of life, though. If any new health care plan indirectly resulted in the substantial increase of my work hours, specifically my night call, I'd struggle with it. Residency is ovah.