It's a little silly to get so angry. I'm disappointed and a little bit annoyed, but not angry. I think that Sakurai should take all the time he wants to make this game. I just wish they wouldn't give a release date and then delay it, especially so close to release.
Although, you have to think with the state that the game industry is in, people demand release dates. I saw it with all the people who wanted a release date announced a year ago, instead of just letting the game go its on course. Sakurai was probably pressured into giving a release date for the game.
Plus, Sakurai is human, and you have to consider what type of situation is. A lot of pressure is being put on Sakurai to release this game, since its going to be Nintendo's big seller. This is his creation, though, and as the third game in the series Sakurai is doing all he can do to make it the perfect Smash Bros. game. I can only imagine how much pressure Sakurai's under. This isn't something he can just release like that.
I wonder what the extra delay is for? It'll be interesting to see.