Do I think Disney would ever approach DC/WB in hopes of using their characters in the parks? I highly doubt it now, since the purchase of Marvel. Do I think it could work or be cool if they did so, absolutely. As a side note, the Wonder Woman TV show is represented in Walt Disney World, as part of the 1970s time capsule mosaics in the lobby of Pop Century. I actually heard rumors, nothing concrete, but rumors that Disney was at one time interested in doing an animated Wonder Woman movie to tie in with their Princess theme, but to have it be different in the fact she's the hero, and not some prince (similar to Mulan). Either way, it never happened, if there was even talks about it to begin with.
I think one issue is that any property has the potential to make for a great ride/area of a theme park. In my earlier post I mentioned that Six Flags uses these characters in roller coasters (and that sort of ride), and has a few other areas, like a Hall of Justice store, and things like that, but that wasn't meant as being critical, as that's the sorts of attractions Six Flags does. Six Flags, unlike Disney and Universal has to deal with winter conditions, and I would imagine that can be very hard to maintain intricate details for different areas. I don't recall seeing a dark ride type experience built by Six Flags, so I have no idea if it's good or not. The last time I saw the Marvel Islands of Adventure at Universal they had basically a Large Hulk coaster (painted green), a Doom Drop ride (that had a few touches to it, but looked nothing like the castle the character operates out of), A generic city street, a Storm g-Force ride which was just an imitation of the tea cups, and an eatery that was themed to Fantastic Four, but was mostly metal themed, and the Amazing Spider-Man ride. With the exception of the Spider-Man ride, I'd almost assume all of those other items to be at Six Flags as well. The themeing of the island was fairly bland and generic with the characters carrying the weight as the decorations.
In terms of the characters of Marvel and DC, both are huge in terms of fan bases and interest. DC right now isn't as popular as Marvel is on the big screen, but in television DC has had several winning series (George Reeves Superman, Adam West Batman, Lynda Carter Wonder Woman, The Adventures of Lois and Clark, Smallville, Arrow, Flash, Supergirl etc (that's not even counting the cartoons)). They are just doing different things, but both are doing a good job of it and are increasing the amount of people who know or have heard of a character. Popularity of characters is difficult to access because it matters on how you wish to view "what is popular?" Is it name recognition, is it knowing details or supporting characters of that character, is it merchandise sales, comic book sales, movie appearances etc. What if the character is a household name, but can't individually sell their own comic, needing to be on a team with other popular characters? Is Catwoman or Lois Lane characters who are parts of the other characters books, more popular then Wonder Woman, a character that has done more in her own name then the other two? If we are solely going off of name recognition, it's possible Robin is #3 before Spider-Man. It's a difficult accessment however you go about it.
Superman, Batman, Spider-Man, Wonder Woman, Wolverine, Captain America, Hulk, and others are household names. Of those, in my opinion (and it's just that), Superman and Batman are different because the world surrounding those characters is iconic. Yes, Superman and Batman's name recognition is off the charts (as are the others listed above), but so to is Bruce Wayne, Robin, Joker, Catwoman Batmobile, Gotham, Clark Kent, Lois Lane, Daily Planet, Kryptonitie, Lex Luthor, Metropolis, Smallville etc. I'm not sure how many, if there are others, that could claim that. Let alone is Superman a household name, his best friend, his workplace, his weakness, and the town he grew up in are household names. Superman, Batman and Wonder Woman have been in continuous publication since Pearl Harbor. When superheroic comics were cancelled across the board, including Captain America, and every other superhero title Marvel (then called Timely) had, those three continued to be published. (Aquaman, Green Arrow and Superboy appeared in backup stories, and Plastic Man and Captain Marvel may have had periods they were published after .)Then eventually came the reemergence of Flash, then Green Lantern, and then the Justice League. That inspired Marvel to give superheroic comics another shot, as they had just been making romance, western, and monster books. That "other shot" was in the 60s, and almost everything Marvel threw on the walI, became a blockbuster title.
I completely agree with the person who mentioned longevity. It is not a certainty a comic book can last 5 years, or even 1. For those comics characters to have lasted to the point that people who have never walked into a comic book store know them, some of which call themselves fans (and once again have never been in a comic shop), speaks to the levels that those characters have mattered not just to their generation, but every generation since. If you are a fan of Batman, and have never once set foot in a comic book shop, then that shows the impact of the character. Just like all the people who have never ever seen a Mickey Mouse cartoon, but bought that plushy of him on their first trip to Disney World and fell in love. People may not like them, or may think they are trivial, but the merchandise sales, the fandoms, the conventions, the stories say otherwise. It could be argued, that Superman is the single most significant character created during the 20th Century in any genre. In truth, I love Mickey Mouse, so I'm always going to vote for that, but those characters have mattered and inspired thousands upon thousands. We talk a lot about Harry Potter on these forums, as well we should because he is a great character, a great service to children learning to read, and a character who has branched out into other mediums. Harry Potter however is nothing in comparison to Superman. Whereas Harry Potter is becoming an institution, Superman already was before Potter was even created. Potter's never had a TV show, to my knowledge he's never had a cartoon, though maybe he has. He's never had a radio show, never had a strip in the newspaper, etc. Superman has done pretty much....everything. I think if given the opportunity in a setting like a theme park, they'd be successful, just like they have been. Whether we'll ever see that though is a completely different story.