The demo at E3 and character reveals shed a lot more light on the complete roster for SSB for 3DS & Wii U. While there is still room for surprises, based on the leak (which I swear up and down must have been done by Treehouse), this is about as close as we can come for the final character select screen.
The list goes as follows: (as of 6/12/14)
Rosalina & Luma
Zero Suit Samus
Jigglypuff (Possible Mewtwo swap?)
Mr. Game & Watch
Wii Fit Trainers
Cut: Snake, Lucas, Ivysaur, Squirtle
Total: 47 (49 if you count Mii types)
The 3DS version releases in Japan on September 13th and in America on October 3rd. By 9/13 we will know for sure the final roster.