Surprise, surprise, we got two updates today. First up is Yoshi's Final Smash, Super Dragon. When Yoshi gets a Smash Ball, he gets wings and can shoot a jet of fire and fireballs at his opponents.
The second update was the song called "Animal Crossing: Go K.K. Rider!" and is played in Smashville. I'm looking for a mp3 of it so I can add it to the Brawl Music Player I have on this site, so look for that soon.
Source for Yoshi's Final Smash (More Pictures and Info Here)
Source for "Animal Crossing: Go K.K. Rider!" (Listen to it Here)