Nintendo shows games you can play. Then they let people play those games on the floor, and show people online how the games are played via the Treehouse streams.
They're absolutely the No Nonsense Bunch at E3.
This year they only really surprised me by having a version of Smash lined up that I actually want. I didn't expect that. I'd hoped for other surprises though. Later in the summer maybe. We can't ever know with Nintendo anymore.