"Such a radical shift can't possibly avoid being severely disruptive to those plans."
I would suggest that when the DJI doubles the first two years after the FairTax is implemented (as forecast by a couple of nationally known money managers), that will make it relatively easy to shift financial plans for those astute enough to adjust to the new economic environment.
Speaking of disruptive, what would happen of we allowed the current system to continue to grow like a cancer until it collapsed of its own weight? It is now more tha 60,000 pps. and at its current rate of growth will exceed 100,000 pps. by 2010 (assuming the entire system doesn't collapse before then). Signs are everywhere that the system is buckling under its own weight and complexity. Might not that be disruptive?
Please explain what you mean by "pps".