User blog comment:Tepig921/SSB3DS Leaks Fully Confirmed! My Bionis is Ready!/@comment-10388898-20140825222442

Guys, that gameplay video with Bowser Jr. and Shulk is being taken down very quickly due to copyright issues filed Nintendo! I think it's safe to say that while it may not be the final roster, we've got a bunch of new characters on out hands. Here are some links to some webpages with more info and shows that the videos there that are unavailable for the above reasoning:

http://www.gamenguide.com/articles/12679/20140825/super-smash-bros-4-characters-leak-video-of-bowser-jr-and-shulk-seemingly-confirms-full-roster-shown-in-recent-images.htm