I was expecting a double reveal, but now the possibility of not announcing CP11 at E3, so the Smash hype can live on for a few extra months until a Direct like Smash 4's Final Video Presentation airs later this year, sounds quite plausible. I'm conflicted. I won't even bother predicting who they are, though. As much as I need to learn that predictions are naturally likely to be wrong, Smash is so hard to predict that many people won't even try.
As for my other E3 predictions, I think we're definitely getting BotW2, a new Kirby and a new Fire Emblem, might be getting ARMS 2 or a new Donkey Kong and, if I'm extremely lucky, may get a teaser for the next 3D Mario as the 'one last thing'.