Just looking at the situation tactically, might it be that Apple is intentionally close lipped because they know that it will build up a certain amount of tension and publicity? When they release these products after us knowing it's going to happen for a month and the rumor mills fully announcing what it's going to be (and it getting onto the news) by the time they release the product itself, everyone is already dissapointed and let down and frankly, bored.
By staying silent there are in turn no expectations. Tension builds and then when their next products are announced, it triggers a stronger reaction througout the media. When you're as big a company as Apple, just putting a product on your website, it's going to be immediately noticed by the blogs and within a few hours they'll be talking about it in the news: they don't actually need to have a publicity meeting to announce a product because they have a high enough profile that it won't possibly go unnoticed (unlike the Sony's of the world).
By staying silent there are in turn no expectations. Tension builds and then when their next products are announced, it triggers a stronger reaction througout the media. When you're as big a company as Apple, just putting a product on your website, it's going to be immediately noticed by the blogs and within a few hours they'll be talking about it in the news: they don't actually need to have a publicity meeting to announce a product because they have a high enough profile that it won't possibly go unnoticed (unlike the Sony's of the world).