Wow this thread grows fast.
I hope the stages part of the leak isn't true. It either shows that whoever took the photo had not unlocked many stages or that the stage selection isn't very good. In case this is the definite stage list, I hope the Wii U version has a better selection that represents all franchises.
Regarding the leak, it's slightly weird that Nintendo would risk sending a video with so many newcomers to ESRB. Rules say they should send the stuff that is important to the ranking so I don't see why they would put almost everything in the video. Theoretically they would need to show Wario and other "crude" characters, no need to show Bowser Jr., Dr. Mario, Dark Pit and others. Of course, ESRB thing could just be used to mislead people.
If characters are time locked, I could see stages being time locked too. I could also see Sakurai have a stage available with the DLC characters. Let's assume that the remaining five characters outside of DLC are Dixie Kong, Mewtwo, Ridley, Mach Rider, and Impa. We'd get:
Lucas - Past Stage: New Pork City (ew)
Wolf O'Donnell - A new Star Fox stage
Chorus Kids - A Rhythm Heaven stage
Snake - Shadow Moses
Ice Climbers - A new Ice Climber stage
Impa - Past Stage: Temple
Dixie Kong - A new Donkey Kong stage
Mewtwo - A new Pokémon stage/old Pokémon stage
Mach Rider - A Mach Rider stage
Ridley - Pyrosphere