What you describe is becoming more common, but I wouldn't count on seeing any increase in the number of RV parks in the near future, or for quite some time. If even available, land prices in most sectors of the country reflect the current robust economy. High prices will not interest anyone in building, or even expanding an existing RV park right now.
At the same time, more and more people are hitting the road. The 'full time' demographic is exploding. The most likely short term scenario will be that many RV owners will become disillusioned with the lack of camping space and the increasing need to make reservations months in advance. Not everyone wants to boondock, or spend every night at Walmart. That constant hassle will prompt many to sell their RV. I predict a plethora of seldom used RVs of every type to hit the market "for sale" in the next few years.
