It's too bad that Disneyland doesn't have their own version of Fort Wilderness. That is definitely one aspect that sets WDW apart from other major theme parks. The only other theme park I am aware of that offered RV spaces was CaroWinds, and they had it planned just as well as WDW, albeit not as deluxe. I am amazed that more theme parks don't at least offer some sort of RV hookup. I have tried to find RV parks near Fiesta Texas (Six Flags) and there just aren't any close by.
When we lived on the East Coast, staying on-property at WDW was only possible by dragging our RV along, but that taught us how much nicer and convenient an on-site stay was. Now that it is just the DW and I, we can afford to stay onsite at moderates. Of course we have to fly to get there now. It would take two days each way just to get to Kissimee from here!