The whole thing is just to tie into "Civil War" and put Spider-Man between Iron Man and Captain America, regarding the Superhero Registration Act. Superman's costume change was basically a media stunt. The Knight Trilogy in Batman was done to show fans why Batman should not be like the Punisher or Wolverine. The problem was that in the 90's, such gimmicks got abused by both companies. Though, Batman's costume has evolved over the years. As have most of the comic characters. Batman had different looking ears, cape, utility belt and gloves in the beginning. The yellow oval was added to create a copyright image. The darker costume was created in light of the films. The current suit was created since many felt that it should be back to basics, but keeping Frank Miller's utility belt. Superman's S-Sheild changed a lot, as did his boots. Spider-Man's eyes changed from Steve Ditko to John Romita Sr. to Todd McFarlane. Wolverine went from Herb Temple's design, to Dave Crockum to John Byrne to Dave Crockum to Bryan Hitch to John Cassady to John Byrne. Robin went from Bob Kane and Jerry Robinson to Neal Adams to the new design post OYL. And lets not forget that Dick Grayson gave way to Jason Todd to Tim Drake with Stephanie Brown for a while.