It looks like Peach isn’t the only character whose Brawl appearance may have been confirmed before Sakurai’s introduced them. A piece published online by (fairly reputable) video game magazine Game Informer features an interview with Eiji Aonuma, a developer who’s worked with Zelda games since The Ocarina of Time on the N64. What could an interview focused on Zelda on the DS reveal about Brawl?
GI: Have you been consulted at all for the usage of Link or Sheik or Ganondorf for Smash Bros. Brawl?
Aonuma: I’ve been working with Sakurai for a very long time with this new Smash Bros., because the Wii came out and when discussion for a new Smash Bros. took place nobody could think of anyone other than Sakurai working on it. He was kind of the default, and I was very happy to hear that he would be working on it. Actually, my designers did work on the designs for Sheik and Link and Ganondorf. So they submitted the initial designs, and so it would fit in the Smash Bros. Brawl environment, they’ve had to tweak some of the designs. But Sakurai has brought those altered designs to NCL. We’re working very closely with the team of Smash Bros. Brawl to make sure the characters look their best.
see metakirbyknight sheik is kinda confirmed