Okay, first thing: Ice Climbers and Mr. Game and Watch are getting sacked! That's official news if you wish to look it up. Second: not all clones are going. They are being reworked though so that they won't be clones anymore. Third: some recent news (though it isn't official, so it has to be labled a rumor) states that in a radio show in Japan, Sakurai revealed three new characters; Ridley (which would be great and wouldn't make Pit the only one with wings), Wind Waker Link (to replace Young Link), and Bowser Jr.
And after all that is said, I hope Mewtwo stays! He is one of my best guys!