This is basically where we're headed, irrespective of the PPACA. The current fee-for-service environment is unsustainable, and isn't delivering the outcomes one would expect for the costs.
Healthcare costs are directly tied to the robustness of a nation's primary care infrastructure, and the emphasis placed on prevention and chronic disease management. Chronic diseases are bankrupting our system. By working to prevent these in the first place, and by optimizing the care for those who have them, serious (and expensive) complications are avoided. Having a single physician who coordinates care in a team-based model is far more efficient and cost-effective than our present fragmented "system" wherein many patients have a specialist for every body system, waste and duplication of effort abounds, and cooperation and communication is almost nonexistent. Paying physicians for the quality of care they deliver, based on measured outcomes, rather than as pieceworkers on an assembly line, has the potential to not only improve care, but reduce costs, boost the physician's bottom line, and improve both physician and patient satisfaction.
The devil is in the details, and those remain a work in progress. There are already lots of Patient Centered Medical Home (PCMH) programs in place which have reported excellent results. Google "Patient Centered Primary Care Collaborative" to see what IBM is doing.
ACOs are simply another way to implement the PCMH in an integrated setting which incorporates hospital and specialty care in a risk-sharing model.
Payment in the PCMH setting usually involves a care management fee in addition to fee-for-service, with bonuses for quality, outcomes, and/or cost savings.
http://www.pcpcc.net/
http://www.aafp.org/online/en/home/membership/initiatives/pcmh.html
