I too have been thinking about the status of camping long term and in my view it is going to stay the same or increase. What will take the "hit" is the long distance touring aspect of it in my view.
All types of travel are going up in relative proportion to RV'ing, so flying somewhere and renting a car is going up just as much if not more. People still want to get out and away from the house. Local campgrounds, nearby boon docking, etc. will increase and folks will stay in one spot for longer periods rather than hop from one CG to the next. There will be less travel type wear and tear on RV's so they probably won't be traded in as frequently, the same goes for TV's.
In discussing this issue with many of our camping friends they agree that this is just the start of them rediscovering the local area - in the neighborhood of two or three tanks of fuel outbound to get to a spot that is reasonably far enough away from home that they feel they are "away" from the cares of the day to day grind, but close enough that they can relax. This equates to anywhere from 500 to 1,000 miles which covers a lot of territory and isn't a big financial hit. Other benefits of this type of camping is that people will be using the CG facilities like pools and hot tubs more, and this might put pressure on CG's to keep upgrading their facilities. (Even just two tanks of fuel outbound is actually quite a ways away from home if you think about it.)
When gas hit the high water mark in the seventies and the eighties the only thing I changed from driving big block Chevelles and Corvettes and trucks was my driving habits and that made enough of a difference that life went on. While others were selling off their big block cars to buy Pintos and Chevettes and selling their MoHo's etc. we found some exceptional deals. It looks like this is going to be the case again where we can pick up some really nice highly optioned units for a lot less than we could have were fuel less costly.
I think when people really stop to think about it the vast majority of RV'ers stay within that 1,000 mile radius of home for the biggest part of their camping. They will keep on doing this - they'll just cut back on something else, learn new driving habits, or swallow the ugly pill and just get on with it.
Or that's my opinion.
Barry