Um...I hate to disagree,but...Melee had 14 starters,and in those,Peach and Zelda were included,not to mention,Peach is in the Brawl Boxart,so that may be a hint as to whether she is a starting character,because Sakurai wouldn't make them unlockable if you get them at the beggining of the game,that's kind of stupid when you think about it.and Zelda,if you notice in the videos they released at E for All,Both Princesses are the first ones you see in the begginig of Subspace Emmisary,so I can assume they are starters,just like in Melee,I can also safely assume that Zelda's Final Smash will probably be that she can transform into Sheik.If not,it will probably be the ray of light that she used on Ganon in Ocarina Of Time,or she obtains the Light Arrows from Twilight Princess.
I can also assume that,judging by the way that Mario activated Kirby's trophy and awakened him,that if an Evil Character awakens a good character,Said character is turned into a dark version of themselves,like Dark Link,Dark Fox,Dark Zelda,etc. judging from the color changes in the Smash Dojo Website.