a key plus of that would be that the reimbursement to doctors would be less and there are less administrative costs (the main reason it's cheaper in other countries), and whether to take the option or be a doctor for those on the option... is totally optional. the existing healthcare system can remain for anyone who wants it. there will be obstacles in this process as perhaps the reimbusement should be higher, or there should be more doctors or RNs to service those on that program. or maybe there should be copays and deductibles for those who make enough to pay for it. all these kinks can be worked out as they come. the bottom line though, beyond the details, is that some sort of medicaid public option should exist in the usa.
here are some links arguing for public options of some kind.