Board Thread:Spoilers!/@comment-26311512-20150504124228/@comment-24674051-20150506153932

Before we go crazy, the article (I wish I could find the link, but I remember seeing it) did say no NEW characters. technically the sorcerer is not a new character. He's just a character that we know is hiding in the background. His identity has not been revealed, and that could still be a new actor. They've been chasing him, or referencing him, all season. So I would put forth that revealing the identity of a character is not the same as introducing a new character. Elsa was introducing a new character. Princess Tiana, if they ever go that route, is a new character. The Sorcerer, although rather enigmatic, is not a new character at this point.

I would say, though, that any new actors that show up at this point, unless they get killed off immediately, will carry over to Season 5.