It`s not just the crowd reaction. It`s the whole thing: the feeling of a live presentation, live showing with developers, unscript funny moments, the big screens...
They could do something live aswell - well prepared in advance so people don`t miss it, as most will be busy in lines.
They will have a killer show, i feel it. Of all the years to skip E3 they had to choose this one...
The developer showings are typically sizzle reels anyway, but I agree with the unscripted humorous moments. Nintendo has never taken itself too seriously onstage.