Obviously if you aren't into Zelda, it's a bummer. If you are into Zelda, this is exciting. They are having extensive demos (their own words here) and a FULL DAY of streaming the game. You simply aren't doing that if you plan to spoil the whole game - you're able to do that because the game is absolutely massive, where looking at it for even 14 hours only scratches the surface. This all but ensures this is the longest and largest Zelda game to date.
If you love Zelda and can attend E3, this is like a dream come true. You get an entire massive event dedicated to the game you want. This is unprecedented. No major publisher has ever done this before, and Zelda is the game getting this star treatment. Exciting.
But if Zelda isn't your thing, this kind of sucks. The only hope here is that the NX reveal is a home run with hardware and then a huge home run with the launch lineup and first year lineup. Not just Zelda, but 3D Mario, metroid, pikmin 4, animal crossing NX, massive third party support, etc.