The PCMH is a dream that has fallen through again and again. I honestly don't think it is going to ever come to fruition, but if it did, it would likely lead to an increase in PCP pay as they'd collect the revenues produced by a group of providers. The job would suck, but I can't see PCP pay decreasing after PCMH implementation. What level of a role NPs and PAs versus physicians have in the future is still up for debate- yes, more of them are being advocated for, but much like physicians, PAs and NPs don't much care for PCP work when they can do any number of other things instead. My bet is, they won't start to supplant PCPs until every other market (hospitalists, surgical units, specialist offices, MICUs, etc) is saturated.
Reimbursements have already been increased substantially in the medicaid population- yeah, future talks on rates have stalled, but things are happening at the state level in my state after the number of providers accepting medicaid doubled in a year. So even if things don't pan out at the federal level, it is possible that the states will step up to the plate.