In my opinion, Batman is the best DC Comics hero, and also features the best rouges gallery in comic book history! I think Six Flags should continue to use Batman for new rides and attractions in the future. Here are some ideas I have...
1) Movietown into Gotham City: being that all of the attractions in Movietown are themed to Batman, I think re naming Movietown "Gotham City" would be cool. It would also be perfect if the park ever decided to bring the Batman stunt show back!
2) Flat Rides: some Batman villain themed flat rides would work well in this area.
3) Batman Stunt Show: please Six Flags, BRING BACK THE BATMAN STUNT SHOW! It was one of my favorite shows to see at the park when I was a kid. To add to it, use some new villains besides just Joker and Catwomen. Scarecrow, Joker, and Harley Quinn would be quiet and interesting show.
4) Escape From The Asylum: during Fright Fest, in the Escape From The Asylum maze, i think it would be really cool to see some of Batman's villains in the asylum. Of course only villains that can fit the asylum theme. Joker, Harley Quinn, and Scarecrow would work very well for this! Maybe even Killer Croc, Bane, and Hugo Strange too.