QSK,
Unless airports put these infrastructure upgrades in place, WAAS could not offer any improved operational benefits as the approach minima would essentially have to be the same as the existing minima afforded by our conventional NPAs.
To my knowledge, no extra/improved infrastructure has been put in place for RNP approaches at regional airports, but the minimas have come down to around 250ft AGL from the GPS NPA average of 400ft AGL. Why wouldn't the situation be the same for WAAS approaches?