I really don't think cuts from Brawl are going to be as big as people think.
As Sakurai has said, we shouldn't expect everybody back. But did some of you know what the interviewer asked?
He asked if all characters from the entire series would be back. This includes Young Link, Dr. Mario, Pichu, Roy and Mewtwo, and the Brawl roster.
So really, there's some wiggle room there. If you ask me, Lucario and Ike are pretty much necessities when it comes to Smash (Ike on a larger note). Both are popular characters and maintain their popularity now.
Also, I don't think it's a matter of a character getting deliberately excluded as much as it is who is top priority as opposed to low priority. Last time the only reason Mewtwo and Roy probably didn't make it was because of SANIC. So unless there are complications, there shouldn't be many cuts, if there are any at all. I'd rather they keep the Brawl roster and add fewer newcomers to be honest.