For those that don't know, I have a source within Nintendo who revealed that Sonic would be revealed at the conference and that Brawl would be playable at E for All, both of which turned out to be true. I also revealed the starting roster, which is Mario, Bowser, Peach, Wario, Donkey Kong, Diddy Kong, Link, Zelda/Sheik, Kirby, Meta Knight, Pikachu, Pokemon Trainer, Samus, Fox, Pit, Yoshi, Ike, Ice Climbers, Lucas, Captain Falcon, and Tom Nook.
Well, I got in contact with my source again. I didn't get much, but what I did get is that Captain Olimar is indeed playable and will be an unlockable character. Also, this mysterious screenshot feature that was blurred out in today's update has to do with the new voting channel features Nintendo announced at the Japan conference. And lastly, Nintendo is considering a demo release this year, though the details and if it will actually happen are unknown.