User blog comment:Tepig921/SSB3DS Leaks Fully Confirmed! My Bionis is Ready!/@comment-25161957-20140826095304/@comment-10733804-20140826121206

I'm pretty sure they are from the same source. The Yoshi's Island stage from Brawl that was in the footage (previously unconfirmed for SSB3DS) is in the stage select screen here. Shulk has the same artwork on the bottom screen too. The pictures came first and the footage contained stuff shown in the pictures so if the footage is real than the pictures are real too.

I don't think I believe these "text leaks". They have no sources other than what people say.